For how many weeks will Steven need to deposit money into his savings account before he can pay back his sister and buy the bike?

Question

Steven wants to buy a $565 bicycle. Steven has no money saved,but will be able to deposit $30 into a savings account when he receives his paycheck each Friday. However, before Steven can buy the bike,he must give his sister $65 thathe owes her. For how many weeks will Steven need to deposit money into his savings account before he can pay back his sister and buy the bike?

Answer 1

bike = $565

owed = $ 65

total owed = $630

630/30 = 21 weeks he will need to deposit money

Answer 2

If I were his sister I would not wait. I would demand the first and second $30 and part of the fourth to repay the debt.

That is three weeks with $25 for the savings account.

He now must save and additional $540. 

How many weeks at $30 a week?