Bernardo is saving up money to pay off a debt. His father loaned him $90 and is charging him $1 interest each day. Bernardo earns $20 a day mowing lawns. He only wants to use half of his daily earnings to pay off his debt. How many days will it take io so eliminate what the son owes his father.

It will take 10 days

Step-by-step explanation:

Here, we want to know the number of days it will take for Bernardo to clear the debt he owes his father.

We proceed as follows;

Let the number of days be x

So after x days, there will be an interest of x * 1 = $90

So the amount of money he owes his father after x days will be $(90 + x)

After x days, the amount he would have earned from mowing lawns will be x * 20 = $20x

He intend using half of this to clear the loan

Half of this is 20x/2 = $10x

We know that this amount is enough to clear the loan, so we equate this value to the amount he wants to use to clear the loan

So;

90 + x = 10x

90 = 10x - x

9x = 90

x = 90/9

x = 10