Question

When a number is increased by 9%, the result is 99. What is the original number to the nearest tenth?

Answer 1

The original number is 90.8

Explanation:

we know that

`100\%+9\%=109\%=109/100=1.09`

Let

x -----> the original number

The original number multiplied by 1.09 must be equal to 99

so

`1.09x=99`

Solve the linear equation for x

Divide by 1.09 both sides

`x=99/1.09`

`x=90.8`