PSLE
Irene and Shannon folded paper stars over two days. On Wednesday, Irene folded 58 paper stars more than Shannon. On Thursday, Irene folded another 20 paper stars and Shannon folded another 13. At the end of the two days, Irene made ⁷₉ of the total number of stars. What was the number of paper stars that Irene folded?

	Irene	Shannon	Difference
Before	1 u + 58	1 u	58
Change	+ 20	+ 13
After	1 u + 78	1 u + 13	65
Comparing between Irene and Shannon in the end	7 p	2 p	5 p

Difference between the number of paper stars that Irene and Shannon folded in the end is repeated.

Difference between the number of paper stars that Irene and Shannon folded in the end
= 7 p - 2 p
= 5 p

Difference between the number of paper stars that Irene and Shannon folded in the end
= (1 u + 78) - (1 u + 13)
= 1 u + 78 - 1 u - 13
= 78 - 13
= 65

5 p = 65

1 p = 65 ÷ 5 = 13

Number of paper stars that Irene folded
= 7 p
= 7 x 13
= 91

Answer(s): 91