GMAT PREP EXAM QUESTIONS AND ANSWERS
What are the first ten prime numbers? - Answer-2, 3,5, 7, 11, 13, 17, 19, 23, 29
Sum of two primes - Answer-All prime numbers are odd, except the number 2. Thus, the
sum of any two primes will be even unless one of those primes is the number 2
If a sum of primes is odd, one of those primes must be the number 2
Counting total factors - Answer-If a number has prime factorization a^w x b^y x c^z (where a, b, and c are all prime), then the number has (w +1)(y + 1)(z + 1) different factors
Perfect squares - Answer-1) All perfect squares have an odd number of total factors, which always sum up to an odd number
2) Prime factorization of a perfect square contains only even powers of primes
Should vs. Must - Answer-Must = binding obligation
Should = moral obligation
Relative pronoun rules - Answer-That - if the clause is essential, it must begin with "that"
rather than "which"
Who/whom - must modify people
Which - cannot modify people
Whose - can modify people or things
Which/whom - sometimes follow prepositions
Where - can modify a noun place but cannot modify metaphorical place (condition, situation, circumstances, arrangement)
When - modify a noun event or time; "in which" can also be used instead of when
Words used for two things vs. three or more - Answer-Use between only with two things
or people. Use among when talking about three or more things or people
Is it ok to insert a comma before because? - Answer-Acceptable if "because" is a subordinating conjunction; in that case, it can be separated from a main clause by a comma. If there are two possible interpretations without including a comma, there needs
to be a comma
If "because" is imperative for the rest of the sentence, don't separate it with a comma
Also, do not use "because" after "the reason". Use "the reason" plus "that"
Incorrect: The reason he left is because he was frustrated
Correct: The reason he left is that he was frustrated
Like vs. As - Answer-"Like" is used to compare nouns, pronouns, or noun phrases "As" can be used to compare two clauses
Right: Like her brother, Ava aced the test
Right: As her brother did, Ava aced the test
Comparative and Superlative - Answer-Do not compare an adverb that ends in -ly by changing the ending to -er
Wrong: He runs quicker than Jacob.
Right: He runs more quickly than Jacob.
Some adverbs that do not end in -ly are made into comparatives by adding -er
Right: He runs faster than Jacob.
Do not use a comparative adjective unless you have a than in the sentence
Wrong: With winter coming, I will have higher energy bills
Right: I will have higher bills than last year
Pronouns - Answer-"This" and "These" are never used as standalone pronouns, nor are
"that" and "those"
Idioms for "ability..." and "capability..." - Answer-Wrong: ability of doing...
Right: ability to do...
Right: capability of doing...
Compound Subjects - Answer-If two nouns disagree in number with an "or" conjunction,
use the noun closest to the verb to determine agreement
Right: Either the manager or the employees take a break
Right: Either the employees or the manager takes a break
Colon rules - Answer-What comes before the colon must be able to stand alone as a sentence
You can insert "namely" or "that is" after the colon, and the result would still be acceptable
Right: I love listening to many kinds of music: namely, classical, rock, rap, and pop
Whatever needs explanation should be placed as close to the colon as possible
Worse: Three factors affect the rate of a reaction: concentration...
Better: The rate of a reaction is affected by three factors: concentration...
The clause after the colon must explain what precedes the colon What to consume during test - Answer-During the break after IR, eat something with protein, fat, and complex carbs. During the break after Quant, drink glucose (coconut water)
What property do all terminating decimals share? - Answer-The simplified denominator of the decimal must contain only 2's and 5's as prime factors. For example, 7/250 is a terminating decimal 0.028, as 250 equals to 2 x 5^3. Fraction 3/30 is also a terminating decimal because 3/30 = 1/10 and denominator 10 = 2 x 5
"view X as Y" or "view X to be Y" ? - Answer-view X as Y
Ex: Many financial experts believe policy makers at the Federal Reserve, now *viewing*
the economy *as* balanced between moderate growth and low inflation, are almost certain to leave interest rates unchanged.
Is "media" singular or plural? - Answer-Plural
Equation for the sum of the degree measures of the n interior angles of a polygon - Answer-180(n - 2)
Each of 90 students participated in at least one of three track tryouts: high jump, long jump, and 100-meter dash. If 20 students participated in the high jump, 40 students in long-jump, and 60 students in 100-meter dash, and if 5 students participated in all three tryouts, how many students participated in only two of these tryouts? - Answer-Let x be the number who participated in exactly 1 of the tryouts, y be 2 of tryouts, z be 3 of tryouts. Then x + y + z = 90 and x + 2y + 3z = 120. It is given that z = 5, so x + y = 85 and x + 2y = 105. Thus, y = *20*
Equation for the sum of the first n terms in an arithmetic sequence - Answer-(n/2)(A1 + An)
A train traveled from Station A to B at ave speed of 80 km/hr and from Station B to C at ave speed 60 km/hr. If the train didn't stop at Station B, what was the average speed at which the train traveled from Station A to C?
1) The distance that the train traveled from A to B was 4 times the distance from B to C
2) The amount of time it took the train to travel from A to B was 3 times the amount of time that it took the train to travel from B to C - Answer-*Time = Dist / Speed*
d1/80 is the amt. of time it took to travel from A to B, and d2/60 is the amt. of time it took
to travel from B to C. We want to find average speed from A to C, given by Total Dist / Total Time = (d1 + d2) / ( (d1/80) + (d2/60) )
1) gives d1 = 4d2, which plugged into the above yields an answer
What are the first ten prime numbers? - Answer-2, 3,5, 7, 11, 13, 17, 19, 23, 29
Sum of two primes - Answer-All prime numbers are odd, except the number 2. Thus, the
sum of any two primes will be even unless one of those primes is the number 2
If a sum of primes is odd, one of those primes must be the number 2
Counting total factors - Answer-If a number has prime factorization a^w x b^y x c^z (where a, b, and c are all prime), then the number has (w +1)(y + 1)(z + 1) different factors
Perfect squares - Answer-1) All perfect squares have an odd number of total factors, which always sum up to an odd number
2) Prime factorization of a perfect square contains only even powers of primes
Should vs. Must - Answer-Must = binding obligation
Should = moral obligation
Relative pronoun rules - Answer-That - if the clause is essential, it must begin with "that"
rather than "which"
Who/whom - must modify people
Which - cannot modify people
Whose - can modify people or things
Which/whom - sometimes follow prepositions
Where - can modify a noun place but cannot modify metaphorical place (condition, situation, circumstances, arrangement)
When - modify a noun event or time; "in which" can also be used instead of when
Words used for two things vs. three or more - Answer-Use between only with two things
or people. Use among when talking about three or more things or people
Is it ok to insert a comma before because? - Answer-Acceptable if "because" is a subordinating conjunction; in that case, it can be separated from a main clause by a comma. If there are two possible interpretations without including a comma, there needs
to be a comma
If "because" is imperative for the rest of the sentence, don't separate it with a comma
Also, do not use "because" after "the reason". Use "the reason" plus "that"
Incorrect: The reason he left is because he was frustrated
Correct: The reason he left is that he was frustrated
Like vs. As - Answer-"Like" is used to compare nouns, pronouns, or noun phrases "As" can be used to compare two clauses
Right: Like her brother, Ava aced the test
Right: As her brother did, Ava aced the test
Comparative and Superlative - Answer-Do not compare an adverb that ends in -ly by changing the ending to -er
Wrong: He runs quicker than Jacob.
Right: He runs more quickly than Jacob.
Some adverbs that do not end in -ly are made into comparatives by adding -er
Right: He runs faster than Jacob.
Do not use a comparative adjective unless you have a than in the sentence
Wrong: With winter coming, I will have higher energy bills
Right: I will have higher bills than last year
Pronouns - Answer-"This" and "These" are never used as standalone pronouns, nor are
"that" and "those"
Idioms for "ability..." and "capability..." - Answer-Wrong: ability of doing...
Right: ability to do...
Right: capability of doing...
Compound Subjects - Answer-If two nouns disagree in number with an "or" conjunction,
use the noun closest to the verb to determine agreement
Right: Either the manager or the employees take a break
Right: Either the employees or the manager takes a break
Colon rules - Answer-What comes before the colon must be able to stand alone as a sentence
You can insert "namely" or "that is" after the colon, and the result would still be acceptable
Right: I love listening to many kinds of music: namely, classical, rock, rap, and pop
Whatever needs explanation should be placed as close to the colon as possible
Worse: Three factors affect the rate of a reaction: concentration...
Better: The rate of a reaction is affected by three factors: concentration...
The clause after the colon must explain what precedes the colon What to consume during test - Answer-During the break after IR, eat something with protein, fat, and complex carbs. During the break after Quant, drink glucose (coconut water)
What property do all terminating decimals share? - Answer-The simplified denominator of the decimal must contain only 2's and 5's as prime factors. For example, 7/250 is a terminating decimal 0.028, as 250 equals to 2 x 5^3. Fraction 3/30 is also a terminating decimal because 3/30 = 1/10 and denominator 10 = 2 x 5
"view X as Y" or "view X to be Y" ? - Answer-view X as Y
Ex: Many financial experts believe policy makers at the Federal Reserve, now *viewing*
the economy *as* balanced between moderate growth and low inflation, are almost certain to leave interest rates unchanged.
Is "media" singular or plural? - Answer-Plural
Equation for the sum of the degree measures of the n interior angles of a polygon - Answer-180(n - 2)
Each of 90 students participated in at least one of three track tryouts: high jump, long jump, and 100-meter dash. If 20 students participated in the high jump, 40 students in long-jump, and 60 students in 100-meter dash, and if 5 students participated in all three tryouts, how many students participated in only two of these tryouts? - Answer-Let x be the number who participated in exactly 1 of the tryouts, y be 2 of tryouts, z be 3 of tryouts. Then x + y + z = 90 and x + 2y + 3z = 120. It is given that z = 5, so x + y = 85 and x + 2y = 105. Thus, y = *20*
Equation for the sum of the first n terms in an arithmetic sequence - Answer-(n/2)(A1 + An)
A train traveled from Station A to B at ave speed of 80 km/hr and from Station B to C at ave speed 60 km/hr. If the train didn't stop at Station B, what was the average speed at which the train traveled from Station A to C?
1) The distance that the train traveled from A to B was 4 times the distance from B to C
2) The amount of time it took the train to travel from A to B was 3 times the amount of time that it took the train to travel from B to C - Answer-*Time = Dist / Speed*
d1/80 is the amt. of time it took to travel from A to B, and d2/60 is the amt. of time it took
to travel from B to C. We want to find average speed from A to C, given by Total Dist / Total Time = (d1 + d2) / ( (d1/80) + (d2/60) )
1) gives d1 = 4d2, which plugged into the above yields an answer
