Quantitative: Number Properties Flashcards

7 cards from real GMAT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Quantitative: Number Properties flashcards as text

If n is a positive integer, which of the following must be even?
Answer: n(n+1)
The product of two consecutive integers is always even because one of them must be even.
What is the units digit of 7^23?
Answer: 3
Powers of 7 cycle 7,9,3,1 with period 4, and 23 mod 4 = 3, giving units digit 3.
How many positive divisors does 36 have?
Answer: 9
Since 36 = 2^2 * 3^2, the divisor count is (2+1)(2+1) = 9.
If x is an odd integer, which expression is always odd?
Answer: 3x
An odd number times an odd number is odd, so 3x stays odd.
What is the remainder when 47 is divided by 6?
Answer: 5
Since 6 * 7 = 42, the remainder is 47 - 42 = 5.
Which of the following is a prime number?
Answer: 83
83 has no divisors other than 1 and itself, while 91=7*13, 87=3*29, and 51=3*17.
If the sum of three consecutive integers is 72, what is the largest of them?
Answer: 25
The middle integer is 72/3 = 24, so the three are 23, 24, 25 and the largest is 25.