PSLE
Shiyun and Xylia folded paper balls over two days. On Wednesday, Shiyun folded 39 paper balls more than Xylia. On Thursday, Shiyun folded another 23 paper balls and Xylia folded another 10. At the end of the two days, Shiyun made ⁷₁₀ of the total number of balls. What was the number of paper balls that Shiyun folded?

	Shiyun	Xylia	Difference
Before	1 u + 39	1 u	39
Change	+ 23	+ 10
After	1 u + 62	1 u + 10	52
Comparing between Shiyun and Xylia in the end	7 p	3 p	4 p

Difference between the number of paper balls that Shiyun and Xylia folded in the end is repeated.

Difference between the number of paper balls that Shiyun and Xylia folded in the end
= 7 p - 3 p
= 4 p

Difference between the number of paper balls that Shiyun and Xylia folded in the end
= (1 u + 62) - (1 u + 10)
= 1 u + 62 - 1 u - 10
= 62 - 10
= 52

4 p = 52

1 p = 52 ÷ 4 = 13

Number of paper balls that Shiyun folded
= 7 p
= 7 x 13
= 91

Answer(s): 91