PSLE
Yen and Emma folded paper balls over two days. On Friday, Yen folded 58 paper balls more than Emma. On Saturday, Yen folded another 15 paper balls and Emma 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	Emma	Difference
Before	1 u + 58	1 u	58
Change	+ 15	+ 8
After	1 u + 73	1 u + 8	65
Comparing between Yen and Emma in the end	7 p	2 p	5 p

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

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

Difference between the number of paper balls that Yen and Emma folded in the end
= (1 u + 73) - (1 u + 8)
= 1 u + 73 - 1 u - 8
= 73 - 8
= 65

5 p = 65

1 p = 65 ÷ 5 = 13

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

Answer(s): 91