Last Updated on May 10, 2023
GMAT OFFICIAL GUIDE PS
Solution:
We are given that Rebecca is 34 years old and that her daughter is 8 years old. We must determine in how many years Rebecca’s age will be twice her daughter’s age.
Let’s let x = the number of years that must pass before Rebecca’s age is twice her daughter’s age. We see that at that time Rebecca will be (34 + x) years old, and her daughter will be (8 + x) years old. Further, we know that, at that time in the future, Rebecca will be two times her daughter’s age.
We can create the following equation to express the relationship between the two ages at that time in the future:
34 + x = 2(8 + x)
34 + x = 16 + 2x
18 = x
Rebecca’s age will be twice the age of her daughter in 18 years. (Rebecca will be 52 and her daughter will be 26.)
Answer: C