Sarah used 1/6 of a bottle of shampoo on her dog Sam, and 1/3 of what was left on her dog Fred. How much of the bottle of shampoo did she use on Fred?

A 1/6

B 1/3

C 5/18

D 1/9

1 answer

Since Sarah used 1/6 of the bottle of shampoo on her dog Sam, the amount left is 1 - 1/6 = 5/6 of the bottle.
Then she used 1/3 of the remaining amount on her dog Fred, which is (1/3) * (5/6) = 5/18 of the bottle.
Therefore, Sarah used 5/18 of the bottle of shampoo on Fred.
The answer is C) 5/18.