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Test your basic knowledge |
GMAT Word Translations
Start Test
Study First
Subjects
:
gmat
,
reading-and-comprehension
Instructions:
Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can
study here
.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.
This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Many word problems with 'how many' are combinatorics. Many combinatorics masquerade as probability problems. Looking for analogies to known problem types will help find a viable solution. Break down complicated counting problems into separate decisio
Disguised Combinatorics
Optimization & Grouping
Probability Trees
Typical time relations
2. Basic motion problems involve rate - time and distance. Rate = ratio of distance and time Time = a unit of time Distance = a unit of distance - Use an RTD chart to solve. Fill in 2 of the variables then use the RT=D formula to solve.
Probability
Basic Motion - The RTD Chart
Prices & Quantities
Weighted Averages
3. Optimization: inversion between finding the min/max and the values givens typical. Be careful to round up or down appropriately. Grouping: determine the limiting factor on the number of complete groups. Think about the most or least evenly distribute
Anagram Grids
Algebraic Translations
Basic Work Problems
Optimization & Grouping
4. 1. Draw empty slots corresponding to each of the choices you have to make. 2. Fill in each slot with the number of options for that slot. Choose the most restricted opt ins first. 3. Multiply the numbers in the slots to find the total number of combi
Anagrams
Probability
Optimization & Grouping
Slot Method (for problems where certain choices are restricted)
5. Be able to write word problems with two different types of equations: - relate the quantities or numbers of different goods - relate the total values of the goods. 1. Assign variables - try to use as few variables as possible. 2. Write equations - fo
Reforming Difficult Problems
Main forms of rate problems
The 1-x Probability Trick
Prices & Quantities
6. Some population that typically increases by a common factor every time period.
Population Problems
Use a population chart
The 1-x Probability Trick
Ratios
7. A rearrangement of the letters in a word or phrase. Count the anagrams of a simple word with n letters by using n! When there are repeated items in a set - reduce the number of arrangements. The number of arrangements of a word is the factorial of th
Combinatorics & the Domino Effect
Weighted Averages
Anagrams
Overlapping Sets & Percents
8. Multiply the probabilities of events in a sequence - taking earlier events into account. When you have a symmetrical problem with multiple equivalent cases - calculate the probability of one case (often using the domino effect rule above). Then multi
Combinatorics & the Domino Effect
Probability Trees
Entirely Unknown Sets
Sample Multiple RTD Problems
9. For problems involving percents or fractions - use smart numbers and a double-set matrix to solve. For problems with percents - pick a total of 100. For problems with fractions - pick a common denominator for the total. You can only assign a number t
Multiple Ratios
Overlapping Sets & Percents
Combinatorics & the Domino Effect
Average Rate: RTD Problems
10. Combination: selection of items from a larger pool where the order doesn't matter. Number of r items chosen from a pool of n items: n!/(n-r)!*r! Permutation: selection of items from a larger pool where the order matters. n!/(n-r)!
The 1-x Probability Trick
Combination & Permutation Formulas
Scheduling
Concrete values
11. Planning a timeline to coordinate events to a set of restrictions. Focus on the extreme scenarios: 1. Be aware of both explicit and hidden constraints.2. Choose the highest or lowest values of the variables. 3. Be very careful about rounding.
Scheduling
Typical time relations
Probability Trees
Arrangements with Constraints
12. Slower/faster - left... and met/arrived at
Typical time relations
Use Charts to Organize Variables
Computation problems
Probability Trees
13. Make a chart when several quantities and multiple relationships. Ex: age problems - people in rows - times in columnsn 1. Assign variables - try to use 1 variable for simplicity. 2. Write equations - use leftover information/relationships to write eq
Use Charts to Organize Variables
Hidden Constraints
Typical time relations
Probability
14. In some probability problems - both the 'desired' possibilities and the total possibilities require counting. Use combinatorial methods to calculate the numbers of possibilities. After finding the numbers - set up the probability as a fraction - 'win
Multiple RTD Problems
Combination & Permutation Formulas
Combinatorics & Probability
Optimization & Grouping
15. Counting the number of possibilities/ways you can arrange things.Fundamental Counting Principle: if you must make a number of separate decisions - then MULTIPLY the numbers of ways to make each individual decision to find the number of ways to make a
Main forms of rate problems
Probability: Multiple Events
Combinatorics
Overlapping Sets & Percents
16. 1. Assign variables - make up letters to represent unknown quantities to set up equations - choose meaningful letters - avoid subscripts - try to minimize the number of variables 2. Write equations - translate verbal relationships into math symbols.
Overlapping Sets: Double-Set Matrix
Algebraic Translations
Rates & Work Problems
Prices & Quantities
17. If a problem has unusual constraints - try counting arrangements without constraints first. Then subtract the forbidden arrangements. Glue Method: for problems in which items or people must be next to each other - pretend that the items 'stuck togeth
Weighted Averages
The Unknown Multiplier
Arrangements with Constraints
Probability
18. Difficult problems involve rates - times and distances for more than one trip or traveler - expand the RTD chart by adding rows for each trip.
Hidden Constraints
Use a population chart
Arrangements with Constraints
Multiple RTD Problems
19. Changes to Mean: Change in mean = New term - Old mean / New number of terms -- Using residuals: Residual = Data point - Mean - Keep track of signs of residuals. The residuals sum to zero in any set. All residuals cancel out.
Reforming Difficult Problems
Rates & Work Problems
Overlapping Sets & Percents
Shortcuts for Averages
20. Can be solved with a proportion. 1. Set up a labeled proportion. 2. Cross-multiply to solve. Cancel factors out before multiplying to save time. Can cancel either vertically within a fraction or horizontally across the equals sign.
Typical rate (speed) relations
Basic Work Problems
Simple ratio problems
Permutation
21. If switching elements in a chosen set creates a different set - it is a ______________. There are usually fewer combinations than permutations.
Use Charts to Organize Variables
Average Rate: RTD Problems
Multiple Arrangements
Permutation
22. Don't just add and divide! If something moves the same distance twice but at different rates - then the average rate will NEVER be the average of the two given rates. The average rate will be closer to the slower of the two rates. Find the total comb
Algebraic Translations
Concrete values
Standard Deviation (SD)
Average Rate: RTD Problems
23. If a probability problem seems to require extensive calculation - try to reformulate it in a way that either takes advantage of symmetry in the problem or groups several individual cases together at once.
Scheduling
Reforming Difficult Problems
Optimization & Grouping
Grouping
24. Put people or items into groups to maximize or minimize a characteristic in the group.
Average Rate: RTD Problems
Grouping
Permutation
Slot Method (for problems where certain choices are restricted)
25. Avoid writing relationships backwards. Quickly check your translations with easy numbers. Write an unknown percent as a variable divided by 100. Translate bulk discounts and similar relationships carefully.
Translating Words Correctly
Average Rate: RTD Problems
Overlapping Sets & Algebraic Representation
Combinatorics & the Domino Effect
26. The numbers in the same row of an RTD table will always multiply across. The specifics of the problem determine which columns will add up into a total row. R x T = D 1. The kiss (or crash) ADD SAME ADD 2. the quarrel (away from) ADD SAME ADD 3. The c
Equations for Exponential Growth or Decay
Multiple Ratios
Translating Words Correctly
Sample Multiple RTD Problems
27. Pay close attention to the wording of the problem to see if you need to use algebra to represent the unknowns.From the relationships in the table - set up an equation to solve for unknowns. With that information - fill in the rest of the double-set m
Proportions
Entirely Unknown Sets
Scheduling & Computation Problems
Overlapping Sets & Algebraic Representation
28. For counting the possible number of ways of putting n distinct objects in order - if there are no restrictions - is n! (n factorial).
Overlapping Sets & Algebraic Representation
Average Rate: RTD Problems
Anagram Grids
Simple Factorials
29. Contains no variables; simply plug and chug. 1. Take careful inventory of qtys - numbers and units. 2. Use math techniques and tricks to solve; assign variables. 3. Draw diagrams - tables and charts to organize the information. 4. Read the problem ca
Computation problems
Optimization
Simple Factorials
Standard Deviation (SD)
30. For sets with an odd number of values - the median is the middle value when in order. For sets with an even number of values - the median is the average of the two middle values. You maybe able to determine a specific value for the median even if unk
Entirely Unknown Sets
Disguised Combinatorics
Median
Anagram Grids
31. Scheduling: focus on the extreme possibilities (earliest/latest time slots). Read the problem carefully!
Overlapping Sets: Double-Set Matrix
Multiple RTD Problems
Scheduling & Computation Problems
Combinatorics & the Domino Effect
32. The average of consecutive integers is the middle term - same for any set with terms that are evenly spaced. The average is the middle term. If the set has two middle terms - take the average of the two middle numbers. To find the average (middle ter
Median
Rates & Work Problems
Averages: Evenly Spaced Sets
Use Charts to Organize Variables
33. If X and Y are independent events - AND means multiply the probabilities. You will wind up with a smaller number - which indicates a lower probability of success. If X and Y are mutually exclusive - OR means add the probabilities. You will wind up wi
Basic Work Problems
Probability: Multiple Events
Rates & Work Problems
Overlapping Sets: Double-Set Matrix
34. For complicated ratio problems - the unknown multiplier technique is useful. Represent ratios with some unknown number/variable to reduce the number of variables and make the algebra easier. You can only use it once per problem. You should use it whe
Anagram Grids
Averages: Evenly Spaced Sets
The Unknown Multiplier
Working Together - Add the Rates
35. Venn diagrams should ONLY be used for problems that involve 3 sets with only 2 choices per set. Work from the inside out when filling in. When filling in each outer level - remember to subtract out the members in the inner levels. To determine the to
Scheduling & Computation Problems
Combinatorics & Probability
3-Set Problems: Venn Diagrams
Typical rate (speed) relations
36. Indicates how far from the average data points typically fall. A small SD indicates a set is clustered closely around the average while a large SD indicates the set is spread out widely. You will not need to calculate an exact SD. GMAT questions invo
Concrete values
Standard Deviation (SD)
Working Together - Add the Rates
Reforming Difficult Problems
37. For problems with only two categories or decisions - use a double-set matrix: Rows correspond to the options for one DECISION - columns correspond to the options for the other DECISION. Last row and column contain totals. Bottom right corner has tota
The Unknown Multiplier
Disguised Combinatorics
Probability Trees
Overlapping Sets: Double-Set Matrix
38. Maximize or minimize a quantity by choosing optimal values.
Optimization
Proportions
Algebraic Translations
Slot Method (for problems where certain choices are restricted)
39. If a GMAT problem requires you to choose two or more sets of items from separate pools - count the arrangements separately. Then multiply the numbers of possibilities for each step.
Shortcuts for Averages
Working Together - Add the Rates
Multiple Arrangements
Slot Method (for problems where certain choices are restricted)
40. Use anagram grids to solve combinations with repetition. Set up an anagram grid to put unique items or people on the top row. Only the bottom row should have repeats. To count possible groups - divide the total factorial by two factorials: one for th
Use Charts to Organize Variables
The Unknown Multiplier
Typical rate (speed) relations
Anagram Grids
41. Twice/half/n times as fast as - slower/faster - relative rates
Average Rate: RTD Problems
Typical time relations
The 1-x Probability Trick
Typical rate (speed) relations
42. = sum/# of terms If you know the average - use this formula: (average) x (# of terms) = (sum) - All that matters is the sum of the terms - not the individual terms. To keep track of two average formulas - set up an RTD-style table.
Averages
Weighted Averages
Use Charts to Organize Variables
Multiple Ratios
43. Quantity that expresses the chance - or likelihood - of an event. To find a probability - you need to know the total number of possibilities and the number of successful scenarios. All outcomes must be equally likely. Use a counting tree to find the
Probability
Main forms of rate problems
Averages
Use a population chart
44. Determine the combined rate of all the workers working together: sum the individual working rates. If one agent is undoing the work of another - subtract their working rates. If a work problem involves time relations - then the calculations are just
Use a population chart
Overlapping Sets & Percents
Overlapping Sets & Algebraic Representation
Working Together - Add the Rates
45. Will be closer to the number with the bigger weight. If the weights don't add to one - sum the weights and use that to divide in order to have a total weight of one. Weighted average = weight/sum of weights(data point) + weight/sum of weights(data po
Typical time relations
Multiple Arrangements
Rates & Work Problems
Weighted Averages
46. In certain types of OR problems - the probability of the desired event NOT happening may be easier to find. If on a problem - 'success' contains multiple possibilities -- especially if the wording contains phrases such as 'at least' and 'at most' --
Proportions
Multiple Ratios
Scheduling
The 1-x Probability Trick
47. Involve time - rate and work.- work: number of jobs completed or items produced - time: time spent working - rate: ratio of work to time - amount completed in one time unit Often have to calculate the work rate. Always express as jobs per unit of tim
Basic Motion - The RTD Chart
Translating Words Correctly
The Unknown Multiplier
Basic Work Problems
48. The order a ratio is given in is vital. To avoid reversals - always write units on either the ratio or the variables.
Basic Motion - The RTD Chart
Combinatorics & the Domino Effect
Multiple Arrangements
Proportions
49. To combine ratios with common elements - multiply all of the ratios by the same number (a common multiple). Make the term you are working with the least common multiple of the current values.
Simple ratio problems
Computation problems
Multiple Ratios
Slot Method (for problems where certain choices are restricted)
50. If you have to construct and manipulate completely abstract sets - use alphabetical order to make the sets a little more concrete. If the problem is complex - create a column chart. Each column is a number in the set. Put the columns in order with t
Entirely Unknown Sets
The Unknown Multiplier
Scheduling & Computation Problems
Probability: Multiple Events