10 years ago, Billy won some money in the lottery and put it in a bank account that earns 15% interest compounded annually. If Billy currently has 500.00 in the bank account, how much interest has he earned?

解

10 ye a rs a g o, B i ll y w o n so m e m o n ey in t h e l o tt ery an d p u t i t in a bank a cco u n t t ha t e a r n s 15% in t eres t co m p o u n d e d ann u a ll y . I f B i ll y c u rre n tl y ha s 500.00 in t h e bank a cco u n t, h o w m u c h in t eres t ha s h e e a r n e d ?

Interest : 376.41

解答ステップ

Translate the problem into an equation:

500 = 123.59235 \dots + I

I

を解く

500 = 123.59235 \dots + I : I = 376.41

Interest : 376.41