Sandra invests $5,000 in a savings account that pays 5% simple interest. How many years will it take for the account to grow to $15,000, if she makes no withdrawals or deposits?

1 Answer
Nov 9, 2016

#40" "#years

Explanation:

The formula for SI is: #SI = (PRT)/100#

To have an account of #$15,000" "(A)# means that she needs to have earned #$10,000# interest on her investment of #$5,000" "(P)#

In simple interest, interest is calculated only on the initial amount.

#SI = (PRT)/100 = 10000#

#(5000xx5xxcolor(blue)(T))/100 = 10000#

#color(blue)(T)= (10000 xx100)/(5000xx5)#

#T = 40# years

#rarr# No one would invest at simple interest!