A person invests 5500 dollars in a bank. The bank pays 4.25% interest compounded quarterly. To the nearest tenth of a year, how long must the person leave the money in the bank until it reaches 8600 dollars?

解

A p erso n in v es t s 5500 d o ll a rs in a bank . T h e bank p a ys 4.25% in t eres t co m p o u n d e d q u a r t er l y . T o t h e n e a res t t e n t h o f a ye a r, h o w l o n g m u s t t h e p erso n l e a v e t h e m o n ey in t h e bank u n t i l i t re a c h es 8600 d o ll a rs ?

Time : 10.57

解答ステップ

Translate the problem into an equation:

8600 = 5500 (1 + \frac{0.0425}{4})^{4 t}

t

を解く

8600 = 5500 (1 + \frac{0.0425}{4})^{4 t} : t = 10.57

Time : 10.57