Question

12. John borrowed $80 from his sister, Joan. He agreed to pay her back at a rate of $6 per

week. Create a function, P, that gives the amount of money that john still owes Joan after

w weeks.


12 (b) John told Joan that he will have paid her back all of the money, after making

payments for 13 weeks.. Explain why John is incorrect?

Answer 1

• P = 80 - 6w

Explanation:

• Initial amount = $80
• Payment each week = $6

Required function:

• P = 80 - 6w

Time required to pay all money. At this time P = 0

• 0 = 80 - 6w
• 6w = 80
• w = 80/6
• w = 13.33

Since w > 13, John needs 14 weeks