PSLE
Erika and Yen folded paper cranes over two days. On Saturday, Erika folded 55 paper cranes more than Yen. On Sunday, Erika folded another 32 paper cranes and Yen folded another 31. At the end of the two days, Erika made ⁷₁₀ of the total number of cranes. What was the number of paper cranes that Yen folded?

	Erika	Yen	Difference
Before	1 u + 55	1 u	55
Change	+ 32	+ 31
After	1 u + 87	1 u + 31	56
Comparing between Erika and Yen in the end	7 p	3 p	4 p

Difference between the number of paper cranes that Erika and Yen folded in the end is repeated.

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

Difference between the number of paper cranes that Erika and Yen folded in the end
= (1 u + 87) - (1 u + 31)
= 1 u + 87 - 1 u - 31
= 87 - 31
= 56

4 p = 56

1 p = 56 ÷ 4 = 14

Number of paper cranes that Yen folded
= 3 p
= 3 x 14
= 42

Answer(s): 42