Question

You put $500 in the bank, where it ears 1.5% simple interest every year. How long until your money will triple?

Answer 1

133.33 years

Explanation:

Given that:

Principal = $500

Interest rate (r) = 1.5% = 0.015

Triple amount of principal = $500 * 3 = $1500 = final amount (A)

Number of years (t) =?

Using the relation :

A = P(1 + rt)

1500 = 500(1 + 0.015t)

1500 / 500 = 1 + 0.015t

3 = 1 + 0.015t

3 - 1= 0.015t

2 = 0.015t

2 / 0.015 = 0.015t / 0.015

133.333 = t

133.33 years