-
vivek.kapoor83
- Legendary Member
- Posts: 833
- Joined: Mon Aug 04, 2008 1:56 am
- Thanked: 13 times
It should be 2.
Choice 'C'. The two numbers are 64 and 96.
BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course
Redeemlength
This topic has expert replies
Source: Beat The GMAT — Problem Solving |
-
sonu_thekool
- Senior | Next Rank: 100 Posts
- Posts: 60
- Joined: Mon Jun 04, 2007 7:37 am
- Thanked: 6 times
-
sonu_thekool
- Senior | Next Rank: 100 Posts
- Posts: 60
- Joined: Mon Jun 04, 2007 7:37 am
- Thanked: 6 times
Since they are asking us to find a 2-digit number with a length of 6 - we need to find numbers from 10-99 with the prime factors.
Since 2 is the lowest prime, try 2x2x2x2x2x2 = 6 factors of 2 = 64
Next try replacing one of the 2s with the next high prime number 3:
2x2x2x2x2x3 = 5 factors of 2 and one 3 = 96
Since we only need numbers from 10-99 no other number with 6 factors would be eligible.
Hope this helps.
Since 2 is the lowest prime, try 2x2x2x2x2x2 = 6 factors of 2 = 64
Next try replacing one of the 2s with the next high prime number 3:
2x2x2x2x2x3 = 5 factors of 2 and one 3 = 96
Since we only need numbers from 10-99 no other number with 6 factors would be eligible.
Hope this helps.
-
logitech
- Legendary Member
- Posts: 2134
- Joined: Mon Oct 20, 2008 11:26 pm
- Thanked: 237 times
- Followed by:25 members
- GMAT Score:730
Think about all the small primes, which ones will you keep it under 100 when you have 6 of them ?
2x2x2x2x2x2 = 64 is a good start.
Our next prime is 3
We can try to replace one of the 2's and try
2x2x2x2x2x3 = 96
This is very close to our border line of 99. and we know that if we ever replace another 2 with 3 , we will cross that line so we should stop here and choose TWO.
2x2x2x2x2x2 = 64 is a good start.
Our next prime is 3
We can try to replace one of the 2's and try
2x2x2x2x2x3 = 96
This is very close to our border line of 99. and we know that if we ever replace another 2 with 3 , we will cross that line so we should stop here and choose TWO.
LGTCH
---------------------
"DON'T LET ANYONE STEAL YOUR DREAM!"
---------------------
"DON'T LET ANYONE STEAL YOUR DREAM!"
Thanks for the responses.
This is actually the approach I took when doing the practice test. However, I had forgotten that 2 was a prime number for some reason and tried it with all 3's which results in a number bigger than 100. But, I understand it now thanks.
This is actually the approach I took when doing the practice test. However, I had forgotten that 2 was a prime number for some reason and tried it with all 3's which results in a number bigger than 100. But, I understand it now thanks.
-
vivek.kapoor83
- Legendary Member
- Posts: 833
- Joined: Mon Aug 04, 2008 1:56 am
- Thanked: 13 times