Question

Mara has 3 times as many dollars as her brother, Timmy. If Mara is given $20 by their mother, she will have 7 times as many dollars as Timmy. How many dollars does Timmy have?

Answer 1

$5

Explanation:

Using algebra to solve this problem.

Let 'x' be Timmy’s amount.

->Mara has 3 times as many dollars as her brother i.e 3x dollars

->If Mara is given $20 by their mother, then expression would be

3x + 20

Since Mara’s new amount is supposed to be seven times Timmy’s

current amount, this forms an equation

3x + 20 = 7x

Solving for 'x'

7x -3x=20

4x = 20

x=20/4

x=5

Timmy has an amount of $5