PSLE
Yen and Lucy folded paper balls over two days. On Wednesday, Yen folded 29 paper balls more than Lucy. On Thursday, Yen folded another 29 paper balls and Lucy folded another 8. At the end of the two days, Yen made ⁷₉ of the total number of balls. What was the number of paper balls that Yen folded?

	Yen	Lucy	Difference
Before	1 u + 29	1 u	29
Change	+ 29	+ 8
After	1 u + 58	1 u + 8	50
Comparing between Yen and Lucy in the end	7 p	2 p	5 p

Difference between the number of paper balls that Yen and Lucy folded in the end is repeated.

Difference between the number of paper balls that Yen and Lucy folded in the end
= 7 p - 2 p
= 5 p

Difference between the number of paper balls that Yen and Lucy folded in the end
= (1 u + 58) - (1 u + 8)
= 1 u + 58 - 1 u - 8
= 58 - 8
= 50

5 p = 50

1 p = 50 ÷ 5 = 10

Number of paper balls that Yen folded
= 7 p
= 7 x 10
= 70

Answer(s): 70