1. Kevin loaned Paul $50 at 10% simple interest per week. How much would Kevin pay back to Paul

if he paid the loan back in:

a) 4 weeks

b) 10 weeks

c) How long until Paul owes $120?

a. $70.

b $100.

c. 14 weeks.

Step-by-step explanation:

The interest per week is 10% of $50

= 0.1 * 50

= $5.

So if he pays it off

In 4 weeks he pays back 50 + 4*5 = $70,

in 10 weeks he pays back 50 + 10*5 = $100.

When he owes $120 we have the equation:

50 + 5x = 120 where x = the number of weeks.

5x = 70

x = 14 weeks.