If you would like to know how many hours will Lena need to work before she can afford to buy the computer, you can calculate this using the following steps:
$900 - $473 = $427
$427 / $7 = 61 hours of yard work
Result: Lena will need to work 61 hours before she can afford to buy the computer.
Cost of the computer that Lena wants to buy = 900 Amount of money saved by Lena = $473 Amount per hour paid by Lena's grandmother = $7 Let us assume the number of hours Lena have to work = x Then 473 + 7x = 900 7x = 900 - 473 7x = 427 x = 427/7 = 61 So Lena has to work 61 hours before she can afford top buy the computer.I hope the procedure is clear enough for you to understand.
