Question

Solve for n in the proportion. If possible, first simplify the known fraction.  

42 : 6 = 28/n

a. n=4
b. n=7
c .n=6
d. n=28

Answer 1

42:6 = 28/n
42/6 = 28/n
42*n = 6*28 ... cross multiply
42*n = 168
42*n/42 = 168/42
n = 4

Answer is choice A

As a check, we would plug n = 4 back into the original equation

42/6 = 28/n
42/6 = 28/4
7 = 7

Answer is confirmed