BTGmoderatorDC wrote: ↑Sat Nov 12, 2022 12:32 am
How many multiples of 4 are there between 16 and 260 ?
A. 128
B. 64
C. 62
D. 61
E. 60
OA
E
Source: Princeton Review
If you're not good at remembering formulas, then another option is to look for a pattern.
So, we want to know how many terms are in the sequence 20, 24, 28, . . .. 252, 256
Notice that:
20 = 4
(5)
24 = 4
(6)
28 = 4
(7)
32 = 4
(8)
.
.
.
252 = 4
(63)
256 = 4
(64)
So, the number of terms in the sequence 20, 24, 28, . . .. 252, 256 is equal to the number of integers from
5 to 64 inclusive.
Well we have a formula (an easy formula) for finding this. We know that the number of integers from x to y inclusive is equal to y-x+1
So, the number of integers from
5 to 64 inclusive is equal to 64-5+1 = 60
Answer: E
