I = P x R x T

 

1.              John just inherited $20,000 and wishes to invest it to use as a down payment for a new house.  His local bank offered him a rate of 9.5% for 3 years.  How much interest will John earn?

 

I = P x R x T

I = 20000 x 0.095 x 3

I = 5700

 

      John will earn $5700 in interest.

 

2.              Bill needs to receive $2000 each year from his investment of $15000.  At what interest rate does he need to invest this money?

 

I = P x R x T

2000 = 15000 x r x 1

2000 = 15000r

0.13333 = r

 

      The interest rate needs to be 13.3%.

 

3.              Jenna has borrowed $500 and will pay 10% annual interest.  How much interest will she pay each month?

 

I = P x R x T

I = 500 x 0.10 x 1/12

I = 4.16666667

 

      She will pay $4.17 interest each month.

 

 


4.              Will won the lottery.  He wants to invest part of his winnings in an account that pays 12% per year and he wants to have $200,000 in this account after 4 years.  How much should he invest in this account?

 

I = P x R x T

200000 = P x 0.12 x 4

200000 = 0.48P

416666.666667 = P

 

      He needs to invest $416666.67 in this account.

 


D = R x T

 

1.              Bill drives at an average rate of 68 mph for 3 hours.  How far has he traveled after the 3 hours?

 

D = R x T

D = 68 x 3

D = 204

 

      Bill traveled 204 miles.

 

2.              Pam is driving from Suwanee to Social Circle to visit friends.  If the distance is 52 miles and her average rate of speed is 65 mph, how long will it take her to get to her friends’ house?

 

D = R x T

52 = 65 x T

0.8 = T

 

      It will take her 0.8 hr or 48 minutes.

 

3.              Mrs. Neal has gone to visit her new grandson in Smyrna, TN.  If the distance from her house to Grayson’s house is 250 miles and the drive takes 4¼  hours, what is Mrs. Neal’s average rate of speed?

 

D = R x T

250 = R x 4.25

58.82 = R

      Her average rate is 58.82 mph.