What is the smallest positive integer n such that, out of the n unit fractions 1/k where 1<=k<=n, exactly half of the fractions give a terminating decimal?
<= means less than or equal to
I think the smallest positive integer = 10
1/2 , 1/4, 1/5, 1/8, 1/10 = 5 terminating decimals.
The other 5 are not:
1, 3, 6, 7, 9 = 5
The SMALLEST positive integer would be 6:
2, 4, 5 are terminating and 1, 3, 6 are not.