Hi there! The answer is 30 hours.
Let the number of worked hours be represented by X.
The total earn of option 1, would then be 10X + 60
The total earn of option 2, would then be 12X
We end up with the following equation:

Subtract 10X from both sides.

Divide both sides by 2.

Therefore, after 30 hours of work Rebecca will earn the same amount of money.