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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. 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)!
Working Together - Add the Rates
Probability: Multiple Events
Combination & Permutation Formulas
Scheduling
2. 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
Concrete values
Entirely Unknown Sets
Sample Multiple RTD Problems
Combinatorics & the Domino Effect
3. Some population that typically increases by a common factor every time period.
Combinatorics & the Domino Effect
Scheduling & Computation Problems
Ratios
Population Problems
4. 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
Permutation
Overlapping Sets: Double-Set Matrix
Typical time relations
Probability: Multiple Events
5. Put people or items into groups to maximize or minimize a characteristic in the group.
The Unknown Multiplier
Basic Motion - The RTD Chart
Grouping
Standard Deviation (SD)
6. 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
Multiple Arrangements
Standard Deviation (SD)
Probability: Multiple Events
Probability
7. 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
Simple ratio problems
Disguised Combinatorics
Proportions
Weighted Averages
8. 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
Ratios
Simple Factorials
Scheduling
Averages: Evenly Spaced Sets
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
Proportions
Multiple RTD Problems
Disguised Combinatorics
Basic Motion - The RTD Chart
10. 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
Combination & Permutation Formulas
Combinatorics
Slot Method (for problems where certain choices are restricted)
11. 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
Equations for Exponential Growth or Decay
Permutation
Anagrams
The Unknown Multiplier
12. = 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.
Computation problems
Averages
Disguised Combinatorics
Median
13. 1. Basic motion problems 2. Average rate problems 3. Simultaneous motion problems 4. Work problems 5. Population problems
Main forms of rate problems
Probability: Multiple Events
Anagram Grids
Proportions
14. 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' --
Probability
The 1-x Probability Trick
Multiple Ratios
Prices & Quantities
15. 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
Disguised Combinatorics
Probability Trees
Concrete values
Reforming Difficult Problems
16. 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
Basic Work Problems
Combination & Permutation Formulas
Prices & Quantities
Typical rate (speed) relations
17. The order a ratio is given in is vital. To avoid reversals - always write units on either the ratio or the variables.
Multiple RTD Problems
Averages
Proportions
Grouping
18. 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
Population Problems
Basic Work Problems
Reforming Difficult Problems
Grouping
19. For counting the possible number of ways of putting n distinct objects in order - if there are no restrictions - is n! (n factorial).
Simple Factorials
Scheduling & Computation Problems
Entirely Unknown Sets
Combinatorics
20. 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
Working Together - Add the Rates
Averages
Shortcuts for Averages
21. 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.
The Unknown Multiplier
Overlapping Sets & Percents
Optimization & Grouping
Algebraic Translations
22. Marked by 3 primary components: rate - time & distance or work. Rate x Time = Distance (RT=D) Rate x Time= Work (RT = W)
Overlapping Sets & Percents
Hidden Constraints
Grouping
Rates & Work Problems
23. Make a table with a few rows with NOW in the middle row. Work forwards and backwards from NOW using the problem's information. Maybe pick a smart number for the starting point - choose a number that makes the math simple.
Combinatorics & Probability
Use a population chart
Simple Factorials
Scheduling
24. 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
Disguised Combinatorics
Overlapping Sets & Percents
Typical time relations
Standard Deviation (SD)
25. 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.
Working Together - Add the Rates
Scheduling
Use a population chart
Multiple Ratios
26. 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
Grouping
Scheduling & Computation Problems
Equations for Exponential Growth or Decay
Use Charts to Organize Variables
27. 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: Multiple Events
The Unknown Multiplier
Permutation
Probability
28. 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
Average Rate: RTD Problems
Probability Trees
Hidden Constraints
Concrete values
29. Express a relationship between two or more quantities. - the relationship they express is division. Can be expressed with the word 'to' - using a colon - or by writing a fraction. Can express a part-part relationship or part-whole. Cannot find the qu
Multiple RTD Problems
Ratios
Combinatorics & Probability
Sample Multiple RTD Problems
30. 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
Slot Method (for problems where certain choices are restricted)
Anagrams
Hidden Constraints
Combinatorics
31. 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
Averages: Evenly Spaced Sets
Computation problems
Weighted Averages
Probability: Multiple Events
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
Overlapping Sets & Algebraic Representation
Ratios
Combinatorics
Median
33. 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.
Basic Motion - The RTD Chart
Simple Factorials
Scheduling & Computation Problems
Reforming Difficult Problems
34. 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
Anagrams
Optimization & Grouping
Overlapping Sets: Double-Set Matrix
Probability Trees
35. 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^(
Averages
Typical rate (speed) relations
Equations for Exponential Growth or Decay
Scheduling
36. Slower/faster - left... and met/arrived at
Typical time relations
Typical rate (speed) relations
Sample Multiple RTD Problems
3-Set Problems: Venn Diagrams
37. 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
Overlapping Sets & Algebraic Representation
Probability: Multiple Events
Average Rate: RTD Problems
Translating Words Correctly
38. 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
Average Rate: RTD Problems
Combinatorics & the Domino Effect
Permutation
Combinatorics & Probability
39. 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
Disguised Combinatorics
Optimization & Grouping
Combinatorics & the Domino Effect
Equations for Exponential Growth or Decay
40. 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
Rates & Work Problems
Overlapping Sets: Double-Set Matrix
Sample Multiple RTD Problems
Overlapping Sets & Algebraic Representation
41. 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.
Overlapping Sets: Double-Set Matrix
Shortcuts for Averages
Simple ratio problems
Optimization & Grouping
42. Difficult problems involve rates - times and distances for more than one trip or traveler - expand the RTD chart by adding rows for each trip.
Probability
Concrete values
Multiple RTD Problems
Basic Work Problems
43. 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
Permutation
Concrete values
Probability: Multiple Events
Standard Deviation (SD)
44. 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
Overlapping Sets: Double-Set Matrix
Anagrams
Multiple Ratios
Combinatorics & the Domino Effect
45. Scheduling: focus on the extreme possibilities (earliest/latest time slots). Read the problem carefully!
Entirely Unknown Sets
Scheduling & Computation Problems
Equations for Exponential Growth or Decay
The Unknown Multiplier
46. Twice/half/n times as fast as - slower/faster - relative rates
Overlapping Sets & Percents
Optimization & Grouping
Working Together - Add the Rates
Typical rate (speed) relations
47. 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
3-Set Problems: Venn Diagrams
The 1-x Probability Trick
Grouping
Proportions
48. 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
Shortcuts for Averages
Anagram Grids
Entirely Unknown Sets
Translating Words Correctly
49. If switching elements in a chosen set creates a different set - it is a ______________. There are usually fewer combinations than permutations.
Optimization
Permutation
Combination & Permutation Formulas
Concrete values
50. 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.
Anagrams
Basic Work Problems
Scheduling
Hidden Constraints