Chapter 4.4, Problem 70SR

To determine

To find: the age of G and E

Answer to Problem 70SR

Gabriel’s age is 20 years and Elisa age is 10 years.

Explanation of Solution

Given:

Gabriel age = 12 years

Elisa’s age = 2 years

Gabriel is twice as old as Elisa

Calculation:

To find their ages when Gabriel is twice as old as Elisa present ages

Gabriel age = 12 years

Elisa’s age = 2 years

Let Gabriel be twice as old as Elisa after x years

Ages after x years

Gabriel’s age= $x+12$

Elisa’s age = $x+2$

According to problem,

  $\begin{array}{l}12+x=2\left(2+x\right)\\ 12+x=4+2x\\ 12-4=2x-x\\ x=8\end{array}$

Ages after x years, that is after 8 years

Gabriel’s age = $x+12$

  $=8+12=20$

Elisa’s age = $x+2$

  $=8+2=10$

Gabriel’s age is 20 years and Elisa age is 10 years.

Conclusion:

Hence, Gabriel’s age is 20 years and Elisa age is 10 years.