Question

Mila is working two summer jobs, making $9 per hour babysitting and $17 per hour lifeguarding. Last week Mila earned a total of $138 and worked 2 more hours lifeguarding than hours babysitting. Determine the number of hours Mila worked babysitting last week and the number of hours she worked lifeguarding last week.

Answer 1

Mila spent 4 hours at baby sitting and 6 hours at life guarding

Solution:

Given that, Mila is working two summer jobs, making $9 per hour babysitting and $17 per hour life guarding

Amount earned from babysitting = $ 9 per hour

Amount earned from life guarding = $ 17 per hour

Last week Mila earned a total of $138 and worked 2 more hours life guarding than hours babysitting

Let "b" represent the number of hours spent babysitting

Then, the number of hours spend at life guarding is b + 2

Also, total amount earned last week = $ 138

Then, we can frame a equation as:

Amount earned from babysitting x number of hours spent babysitting + Amount earned from life guarding x number of hours spend at life guarding = 138

$9 \times b + 17 \times (b+2) = 138\\\\9b + 17b + 34 = 138\\\\26b = 138 - 34\\\\26b = 104\\\\b = 4$

Then, number of hours spent at life guarding:

b + 2 - 4 + 2 = 6 hours

Thus she spent 4 hours at baby sitting and 6 hours at life guarding