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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. To keep track of branching possibilities and 'winning scenarios': label each branch and input the probabilities - on the second set of branches - input the probabilities AS IF the first pick was made - remember the domino effect! - compute the probab
Combinatorics & the Domino Effect
Shortcuts for Averages
Probability Trees
Reforming Difficult Problems
2. 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
Proportions
Overlapping Sets & Algebraic Representation
Averages: Evenly Spaced Sets
Algebraic Translations
3. 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
Grouping
Standard Deviation (SD)
Permutation
Probability: Multiple Events
4. 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
Simple Factorials
Combinatorics & Probability
Simple ratio problems
Combinatorics
5. 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
Slot Method (for problems where certain choices are restricted)
Reforming Difficult Problems
Average Rate: RTD Problems
Shortcuts for Averages
6. Some population that typically increases by a common factor every time period.
Scheduling & Computation Problems
Algebraic Translations
Population Problems
Overlapping Sets & Algebraic Representation
7. 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
Anagram Grids
Ratios
Main forms of rate problems
3-Set Problems: Venn Diagrams
8. You don't need ____________ to find the weights. Having the ratios of the weights will allow you to find the weighted average. Write the ratio as a fraction; use the numerator and denominator as weights. If you are finding a weighted average of rates
Population Problems
Probability
Concrete values
Simple ratio problems
9. 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
Simple ratio problems
Grouping
Main forms of rate problems
Disguised Combinatorics
10. 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
Multiple Arrangements
Scheduling
Combinatorics & the Domino Effect
Typical time relations
11. 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
Main forms of rate problems
Averages
Weighted Averages
Concrete values
12. 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
Translating Words Correctly
Simple Factorials
Arrangements with Constraints
Multiple Ratios
13. Slower/faster - left... and met/arrived at
Overlapping Sets: Double-Set Matrix
Average Rate: RTD Problems
Typical time relations
Reforming Difficult Problems
14. 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
Optimization & Grouping
Scheduling & Computation Problems
Multiple RTD Problems
Translating Words Correctly
15. 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.
Basic Motion - The RTD Chart
Shortcuts for Averages
Typical time relations
Averages
16. Maximize or minimize a quantity by choosing optimal values.
Reforming Difficult Problems
Optimization
Grouping
Algebraic Translations
17. 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
Scheduling
Anagrams
Translating Words Correctly
Overlapping Sets & Algebraic Representation
18. 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.
3-Set Problems: Venn Diagrams
Equations for Exponential Growth or Decay
Scheduling & Computation Problems
Translating Words Correctly
19. Difficult problems involve rates - times and distances for more than one trip or traveler - expand the RTD chart by adding rows for each trip.
Rates & Work Problems
Multiple RTD Problems
Equations for Exponential Growth or Decay
Simple ratio problems
20. I - or interval - amount of time given for the quantity to grow or decay S - or starting value - size of the population at time zero t - or time - is the variable (make sure all time units are the same) x - growth or decay factor - Population = S*x^(
Multiple RTD Problems
Rates & Work Problems
Disguised Combinatorics
Equations for Exponential Growth or Decay
21. 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)!
Combination & Permutation Formulas
Probability: Multiple Events
The 1-x Probability Trick
The Unknown Multiplier
22. 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.
Simple ratio problems
3-Set Problems: Venn Diagrams
Anagram Grids
Overlapping Sets & Percents
23. The order a ratio is given in is vital. To avoid reversals - always write units on either the ratio or the variables.
Simple Factorials
Arrangements with Constraints
Proportions
Entirely Unknown Sets
24. 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
Computation problems
Anagrams
Entirely Unknown Sets
Rates & Work Problems
25. 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.
Averages: Evenly Spaced Sets
Averages
Basic Motion - The RTD Chart
Probability Trees
26. Twice/half/n times as fast as - slower/faster - relative rates
Typical time relations
Typical rate (speed) relations
Basic Motion - The RTD Chart
Combinatorics & Probability
27. 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
Probability: Multiple Events
Overlapping Sets & Percents
Combinatorics
The 1-x Probability Trick
28. 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' --
Combinatorics & Probability
The 1-x Probability Trick
Translating Words Correctly
Weighted Averages
29. 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
Ratios
Prices & Quantities
Probability
Permutation
30. 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
Algebraic Translations
Basic Work Problems
Scheduling & Computation Problems
Concrete values
31. Put people or items into groups to maximize or minimize a characteristic in the group.
Grouping
Proportions
Optimization & Grouping
Rates & Work Problems
32. 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
Population Problems
Optimization & Grouping
Median
Probability
33. Check the problem to see if the are any implied constraints to variables like whole numbers. You can solve a data sufficiency question with little information if whole numbers are involved. You can use a table to generate - organize - and eliminate i
Disguised Combinatorics
Probability Trees
Sample Multiple RTD Problems
Hidden Constraints
34. 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
Arrangements with Constraints
Computation problems
Proportions
Basic Motion - The RTD Chart
35. = 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.
Typical time relations
Averages
Arrangements with Constraints
Multiple Ratios
36. 1. Basic motion problems 2. Average rate problems 3. Simultaneous motion problems 4. Work problems 5. Population problems
Main forms of rate problems
Simple ratio problems
Typical rate (speed) relations
Multiple RTD Problems
37. 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
Sample Multiple RTD Problems
Scheduling
Use Charts to Organize Variables
3-Set Problems: Venn Diagrams
38. If switching elements in a chosen set creates a different set - it is a ______________. There are usually fewer combinations than permutations.
Scheduling
Permutation
Combinatorics & the Domino Effect
The 1-x Probability Trick
39. 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
Multiple Ratios
Combination & Permutation Formulas
Rates & Work Problems
Prices & Quantities
40. For counting the possible number of ways of putting n distinct objects in order - if there are no restrictions - is n! (n factorial).
Median
Simple Factorials
Main forms of rate problems
Basic Work Problems
41. 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
Anagram Grids
Simple Factorials
Working Together - Add the Rates
Optimization
42. 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
Optimization & Grouping
Use a population chart
Sample Multiple RTD Problems
Concrete values
43. 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.
Multiple Ratios
Weighted Averages
Scheduling & Computation Problems
Reforming Difficult Problems
44. 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
Equations for Exponential Growth or Decay
Entirely Unknown Sets
Sample Multiple RTD Problems
Standard Deviation (SD)
45. 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.
Hidden Constraints
Scheduling
Prices & Quantities
Rates & Work Problems
46. 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.
Scheduling & Computation Problems
Arrangements with Constraints
Average Rate: RTD Problems
Multiple Ratios
47. 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
Probability: Multiple Events
Optimization & Grouping
Population Problems
The 1-x Probability Trick
48. 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
Ratios
Weighted Averages
Overlapping Sets: Double-Set Matrix
Multiple RTD Problems
49. 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
The Unknown Multiplier
Algebraic Translations
The 1-x Probability Trick
Weighted Averages
50. Scheduling: focus on the extreme possibilities (earliest/latest time slots). Read the problem carefully!
Scheduling & Computation Problems
Typical time relations
Rates & Work Problems
Averages: Evenly Spaced Sets