PSLE
Albert had a total of 465 short and long erasers. After selling an equal number of both types, he had ¹₄ of the short erasers and ¹₅ of the long ones left. What was the total number of erasers sold?
Fraction of the short erasers sold
= 1 - ¹₄
= ³₄

Fraction of the long erasers sold
= 1 - ¹₅
= ⁴₅

The number of short erasers and long erasers sold is the same.
Make the numerators the same.
LCM of 3 and 4 = 12

³₄ Long erasers = ⁴₅ Short erasers
^3x4_4x4 Long erasers = ^4x3_5x3 Short erasers
¹²₁₆ Long erasers = ¹²₁₅ Short erasers

	Long	Short	Total
Before	16 u	15 u	31 u
Change	- 12 u	- 12 u	- 24 u
After	4 u	3 u	7 u

Total number of erasers at first
= 16 u + 15 u
= 31 u

31 u = 465

1 u = 465 ÷ 31 = 15

Total number of erasers sold
= 12 u + 12 u
= 24 u
= 24 x 15
= 360

Answer(s): 360