Julia is twice as old as her brother Paolo, who is five times as old as their dog Winnie. In 10 years, Julia will be

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Julia is twice as old as her brother Paolo, who is five times as old as their dog Winnie. In 10 years, Julia will be four times as old as Winnie will be then. How old is Paolo?

A. 25
B. 27
C. 30
D. 33
E. 35


OA A

Source: Princeton Review

[Scott@TargetTestPrep]

Julia is twice as old as her brother Paolo, who is five times as old as their dog Winnie. In 10 years, Julia will be four times as old as Winnie will be then. How old is Paolo?

A. 25
B. 27
C. 30
D. 33
E. 35


OA A

Source: Princeton Review

Solution:

We can let J, P, and W = the current ages of Julia, Paolo, and Winnie, respectively.

J = 2P

and

P = 5W

In 10 years, Julia will be (J + 10), and Winnie will be (W + 10), and Julia will be 4 times Winnie’s age. Thus, we have:

J + 10 = 4(W + 10)

From the first two equations, we have:

J = 2(5W) = 10W

Substituting this into the third equation, we have:

10W + 10 = 4(W + 10)

10W + 10 = 4W + 40

6W = 30

W = 5

So P = 5(5) = 25.

Answer: A