He would need to save $22 dollars each week to pay for the bike in 7 weeks.
Step-by-step explanation:
We can figure out how many he has saved up already by multiplying the number of weeks (12) by how much he saved each week ($8) which equals $96. Now we have to subtract $96 from $250 which equals $154. Now we need divide this amount by the remaining weeks until he wants to purchase his bike (7), so 154/7 which equals $22.
So he needs to pay 22 dollars each week to pay off the bike in seven weeks