help my qustion

Question

There are white, blue, and red boats in a marina. Five-sixths of the boats in the marina are white, 2/5

 of the remaining boats are blue, and the rest are red. If there are 12 red boats, how many boats are in the marina?

Answer 1

120 boats total = r+w+b= 12+100+8

5/6 x 120 = 100 white boats

1/15 x 120 = 8 blue boats

1/10 x 120 = 12 red boats