The product X of two prime numbers is between 17 and 55. If

Option B & C can be ruled out as they themselves are prime numbers

18 = 2*9 = 3*6 >> Ignore

44 = 2 * 22 = 4 * 11 >> Ignore

51 = 3*17 >> Answer

Answer = E

I also did sth similar, but I guess sligtly different.

I used the information in the stem to do this:
17<x*y<55

2<x<6, one of them prime between 2 and 6. So, x=3 or x=5
13<y<25, one of them between 13 and 25. So, y=17 or y=19 or y=23

Then I did:
x=18/y, none of the possile values of y give a good x, reject
x=29/y, reject
x=37/y, reject
x=44/y, reject
x=51/y, x=51/3, x=17, accept. ANS E

Hi All,

This question is built around a variety of Number Properties, and you can use those same Number Properties to quickly get to the correct answer:

We're told a series of facts about 2 numbers:
1) They're both PRIME
2) Their PRODUCT is between 17 and 55
3) One number is between 2 and 6
4) The other number is between 13 and 25

We're asked for the product that fits these "restrictions"

First, since both numbers are PRIME and NEITHER can be "2", both numbers are ODD.
Second, (odd)(odd) = odd, so the answer MUST be ODD.
Third, the answer CANNOT be prime, since it has these 2 smaller prime numbers as factors.

So, eliminate the EVENS (Answers A and D) and the PRIMES (Answers B and C).

Final Answer:

GMAT assassins aren't born, they're made,
Rich

Since one of the prime numbers is greater than 2 but less than 6, it can be either 3 or 5.

Since the other prime number is greater than 13 but less than 25, it can be either 17, 19 or 23.

Thus, X must be 3 x 17 = 51.

Answer: E

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.