Problem Solving

help..i could figure out 1 no. 64...but its not correct

It should be 2.

Choice 'C'. The two numbers are 64 and 96.

sonu_thekool wrote:It should be 2.

Choice 'C'. The two numbers are 64 and 96.

Thats great, but what is the best way to go about solving this problem?

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.

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.

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.

Good explantion Logitech