PSLE
Erika and Roshel folded paper stars over two days. On Monday, Erika folded 50 paper stars more than Roshel. On Tuesday, Erika folded another 12 paper stars and Roshel folded another 7. At the end of the two days, Erika made ⁷₉ of the total number of stars. What was the number of paper stars that Roshel folded?

	Erika	Roshel	Difference
Before	1 u + 50	1 u	50
Change	+ 12	+ 7
After	1 u + 62	1 u + 7	55
Comparing between Erika and Roshel in the end	7 p	2 p	5 p

Difference between the number of paper stars that Erika and Roshel folded in the end is repeated.

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

Difference between the number of paper stars that Erika and Roshel folded in the end
= (1 u + 62) - (1 u + 7)
= 1 u + 62 - 1 u - 7
= 62 - 7
= 55

5 p = 55

1 p = 55 ÷ 5 = 11

Number of paper stars that Roshel folded
= 2 p
= 2 x 11
= 22

Answer(s): 22