A sum of money place at compound interest doubles itself in 5 years. In how many years will it amount to eight times itself?	Choose the most appropriate option:
A) 15 years	B) 11 years	C) 12 years	D) 18 years	E) 19 years
100 ---- 200 ---- 5   400 ---- 5   800 ---- 5   ------   15 years   15 yearsnswer: 15 years
<result>A</result>
A sum of money place at compound interest doubles itself in 5 years. In how many years will it amount to eight times itself?