If 7 and 9 are factors of 60n, what is the minimum value of n?

If 7 and 9 are factors of 60n, what is the minimum value of n?

Quiz

Answer/Solution

21

Steps/Work

60n/7*9 should be integer => 2*2*3*5*n/7*3*3 = 2*2*5*n/21 must be an integer
for this to be true n must multiple of 21, thus min of n = 21
hence E