Question

Lucy is 15 years old and has $1000, she invests in a CD paying 8% interest. How many times will her money double by the time she is 60?

Answer 1

5

Explanation:

(1 + i ) ^45 i = interest in decimal 45 = years

(1.08)^45 = ~~ 32

when she is 65 it will be worth 32 000

so it doubles 5 times (1000 2000 4000 8000 16000 32000)