Question

Question 13:

Christine had 0.8 times the amount of money Sarah had. They went shopping and spent
$684 altogether. Christine spent 0.25 of her money and had thrice as much money left
as Sarah. How much money did Sarah spend?

Answer 1

Answer: Let's call Sarah's original amount of money as x. Then, Christine had 0.8x.

After they spent $684 altogether, Christine had 0.8x - 0.25(0.8x) = 0.8x - 0.2x = 0.6x left.

Sarah had x - 684.

Since Christine had thrice as much money left as Sarah, we can write an equation:

0.6x = 3(x - 684)

Expanding the right side of the equation:

0.6x = 3x - 2052

Solving for x:

2.6x = 2052

x = 787.69

So Sarah originally had 787.69 dollars and spent 787.69 - 684 = 103.69 dollars.

Explanation: