The difference between the amounts of interest Katy and Frank paid for their loans is $180
Step-by-step explanation:
The formula of the simple interest is I = Prt, where
P is the amount of the loan
r is the interest rate in decimal
t is the time
Katy took out a 5-year loan for $18,000 and paid 7.00% annual simple interest
∵ The amount of her loan is $18,000
∴ P = 18,000
∵ The annual simple interest is 7%
∴ r = 7% = 7 ÷ 100 = 0.07
∵ The loan is for 5 years
∴ t = 5
- Substitute these values in the formula above
∴ I = 18,000(0.07)(5)
∴ I = 6,300
∴ Katy will pay $6,300 interest for her loan
Frank took out a 6-year loan for $18,000 and paid 6.00% annual simple interest
∵ The amount of his loan is $18,000
∴ P = 18,000
∵ The annual simple interest is 6%
∴ r = 6% = 6 ÷ 100 = 0.06
∵ The loan is for 6 years
∴ t = 6
- Substitute these values in the formula above
∴ I = 18,000(0.06)(6)
∴ I = 6,480
∴ Frank will pay $6,480 interest for his loan
∵ The difference between their interests = 6,480 - 6,300
∴ The difference between their interests = $180
The difference between the amounts of interest Katy and Frank paid for their loans is $180
