How many days will it take for a sum of $4,000 to earn $80 interest if it is deposited in a bank paying ordinary simple interest at the rate of 5%/year?

It will take 146 days to earn an interest of $80.

Step-by-step explanation:

The simple interest formula is:

It is provided that:

I = $80

P = $4,000

r = 5% p.a.

Compute the time required as follows:

Thus, it will take 146 days to earn an interest of $80.