Brad inherited some money from his grandfather and put it in a bank account that earns 7% interest compounded annually. After 2 years, Brad had 800.00 in the bank account. How much interest did he earn?Round your answer to the nearest cent.

解答

B r a d inh er i t e d so m e m o n ey f ro m hi s g r an df a t h er an d p u t i t in a bank a cco u n t t ha t e a r n s 7% in t eres t co m p o u n d e d ann u a ll y . A f t er 2 ye a rs, B r a d ha d 800.00 in t h e bank a cco u n t . Ho w m u c h in t eres t d i d h e e a r n ? R o u n d yo u r an s w er t o t h e n e a res t ce n t .

Interest : 101.25

求解步骤

Translate the problem into an equation:

800 = 698.75098 \dots + I

求解

I, 800 = 698.75098 \dots + I : I = 101.25

Interest : 101.25