Question

Mariah earns $32.75 per week working as a pet sitter. She worked as a pet sitter for 2 weeks. She previously saved $70.99 in allowance money. She spent $12.25 of her total earning to buy video games. Mariah put 1 over 4 of the remaining money in her savings account. Mariah used the following steps to find the total money she put in her savings account:

Step 1: [($32.75 ⋅ 2) + $70.99 − $12.25] ⋅ 1 over 4

Step 2: [$65.5 + $70.99 − $12.25] ⋅ 1 over 4

Step 3: $136.49 − $3.0625 = $133.4275

In which step did Mariah first make an error? Explain, using words, how Mariah can correct her error.

Answer 1

Mariah made an error in Step 2.

To correct her error, Mariah needs to simplify the expression in Step 2 before moving on.

Step 2 should be:

($65.5 + $70.99 - $12.25) * (1/4)

Step 2 can be simplified as follows:

$134.24 * (1/4)

= $33.56