PSLE
Hazel and Betty folded paper cranes over two days. On Monday, Hazel folded 50 paper cranes more than Betty. On Tuesday, Hazel folded another 17 paper cranes and Betty folded another 19. At the end of the two days, Hazel made ⁷₁₀ of the total number of cranes. What was the number of paper cranes that Betty folded?

	Hazel	Betty	Difference
Before	1 u + 50	1 u	50
Change	+ 17	+ 19
After	1 u + 67	1 u + 19	48
Comparing between Hazel and Betty in the end	7 p	3 p	4 p

Difference between the number of paper cranes that Hazel and Betty folded in the end is repeated.

Difference between the number of paper cranes that Hazel and Betty folded in the end
= 7 p - 3 p
= 4 p

Difference between the number of paper cranes that Hazel and Betty folded in the end
= (1 u + 67) - (1 u + 19)
= 1 u + 67 - 1 u - 19
= 67 - 19
= 48

4 p = 48

1 p = 48 ÷ 4 = 12

Number of paper cranes that Betty folded
= 3 p
= 3 x 12
= 36

Answer(s): 36