Final answer:
After borrowing $5 and receiving $20 for babysitting, you subtract the amount borrowed from the amount earned to find that you have $15 left for yourself.
Step-by-step explanation:
The question involves a simple arithmetic calculation of money borrowed and earned. First, you borrowed $5 from a friend. Then, your parents gave you $20 for babysitting your sibling. To find out how much money you have left for yourself, you need to perform this calculation:
Total money received (from babysitting) = $20
Money owed (to the friend) = $5
Total money left for you = Total money received - Money owed
Total money left for you = $20 - $5
Total money left for you = $15
The correct answer is b) $15.