Princeton Review Practice Test

wlvoh · Posted: Wed Feb 28, 2007 6:10 pm Post subject: Princeton Review Practice Test

Q: In a sequence of 13 consecutive integers, all of which are less than 100, there are exactly 3 multiples of 6. How many integers in the sequence are prime?

1.) Both of the multiples of 5 in the sequence are also multiples of either 2 or 3.

2.) Only one of the two multiples of 7 in the sequence is not also a multiple of 2 or 3.

I believe the answer should be E, however the OA given is C.

Can anybody explain this one to me? Thanks.

wlvoh

Argen · Posted: Thu Mar 01, 2007 4:03 pm Post subject:

I agree that the answer should be E. Two sequences that apply to both conditions are 6-18 and 42-54, in which the former has 5 primes and the latter 4. So that would negate the OA answer C.

rajesh_ctm · Posted: Wed Mar 14, 2007 7:43 pm Post subject:

Even I think it is E!
6-18 has 4 prime numbers - 7,11,13,17
42-54 has 3 prime numbers - 43,47,53
66-78 has 3 prime numbers - 67,71,73