They will have made the same amount of money after they have completed 2 hours of work each.
Another easy way to find the answer is to put the two into expressions and combine into an equation:
Put into one equation:
Step 1) Subtract 6.5x from both sides:
Step 2) Subtract 10 from both sides:
Step 3) Divide by 2.5 on both sides:
Step 4) Your answer:
You get the same 2 (hours)
If you need the value (Like how much money they made) then just plug in your x value to both expressions.