Please tell what is wrong with this solution ...I am getting 6 !!!!!
Numbers are 2,3,2^2,5,2*3,7,2^3,3^2,2*5
There are 4 prime numbers involved which are 2,3,5,7.
Since a good subset should have exactly 4 elements which are co-prime, those numbers must choose 1 of these primes as factors without repetition
That means we cannot have 2*3, and 2*5 in the good subset because it will force us to choose a factor twice.
Now , in the remaining numbers,
2 can be chosen from 2,2^2,2^3 ----- (3 ways)
3 can be chosen from 3,3^2------------(2 ways)
5 can be chosen from 5-------------------(1 way)
7 can be chosen from 7-------------------(1 way)
So total number of "good" subsets = 3*2*1*1=6