Answer: They pay in total $228 and you end up paying more for the bike.
Step-by-step explanation: The money you have and what you will save will be: 43.50 + 7.25w
After 10 weeks it is equal to $116.
The money your friend has and the amount they will save will be: 24.50 + 8.75w
After 10 weeks it is equal to $112.
Simplifying those together gives you: 68 + 16w
After 10 weeks it is equal to $228.
I hope this helps. :)
