Gem spent ²₅ of her salary on a lamp and ³₅ of the remainder on a refrigerator. If she saved the remaining $180, how much was her salary?
Fraction of the salary spent on the lamp = ²₅

Fraction of the salary on the remainder
= 1 - ²₅
= ³₅

Fraction of the remainder on savings
= 1 - ³₅
= ²₅

Lamp	Remainder		Total
2x5	3x5		5x5
	Refrigerator	Savings
	3x3	2x3
10 u	9 u	6 u	25 u

The remainder and the total amount on the refrigerator and the savings are the same. Make the remainder and the total amount on the refrigerator and the savings the same.  LCM of 3 and 5 is 15.

Total salary = 25 u

Amount spent of the lamp = 10 u
Amount spent on the refrigerator = 9 u
Amount of savings = 6 u

6 u = 180

1 u = 180 ÷ 6 = 30

Gem's salary
= 25 u
= 25 x 30
= $750

Answer(s): $750