Word Problems

[swerve]

Rob is twice as old as Jodie is now. In 10 years, Rob will be 20 years older than Jodie is at that time. How old is Jodie now?

A. 10
B. 20
C. 30
D. 40
E. 50

The OA is B

Source: Princeton Review

[deloitte247]

Let Rob's age now = r
Let Jodie's age now = j
r = 2j ----- eqn (1)
In 10 years time =>
r + 10 = (j + 10) + 20
r + 10 = j + 30
r = j + 20 where r = 2j
2j = j + 20
j = 20 years

Answer = option B

[Scott@TargetTestPrep]

Rob is twice as old as Jodie is now. In 10 years, Rob will be 20 years older than Jodie is at that time. How old is Jodie now?

A. 10
B. 20
C. 30
D. 40
E. 50

The OA is B

Solution:

We can let R = Rob’s current age and J = Jodie’s current age and create the equation:

R = 2J

If Rob will be 20 years older than Jodie in 10 years, he must also be 20 years older than she is presently. Thus, we have:



R = J + 20

Substituting, we have:

2J = J + 20

J = 20

Answer: B