If a∶b = 2∶3 and b∶c = 5∶3, then a∶b∶c = _____?

8:12:9

2:3:8

10:15:9

None of these

Given:

a:b = 2:3

b:c = 5:3

First, make the b values equivalent:

a:b = 2:3 = 2 × 5 : 3 × 5 = 10:15

b:c = 5:3 = 5 × 3 : 3 × 3 = 15:9

Now, a:b:c = 10:15:9