Mika earns $25 for every 3 hrs of work. calder earns $15 for every 2 hrs of work. if calder works long enough to earn the same amount that mika earns in 9 hrs, how many hrs does he work?

Calder would have to work 10 hours to equal the same amount Mika has from 9 hours of work

Here's how:
Since Mika works 9 hours and she gets 25 per 3 hours, to get her amount for 9 hours, you times 25 by 3 which is 75

Now you need to set up a equation
To make it easier. you can divide 15 by 2, which is 7.5, to get a unit rate
After that you can set up your equation
7.5x=75
x=10
Hope this helps:)