PSLE
Cindy and Abi folded paper balls over two days. On Monday, Cindy folded 10 paper balls more than Abi. On Tuesday, Cindy folded another 37 paper balls and Abi folded another 11. At the end of the two days, Cindy made ⁷₁₀ of the total number of balls. What was the number of paper balls that Abi folded?

	Cindy	Abi	Difference
Before	1 u + 10	1 u	10
Change	+ 37	+ 11
After	1 u + 47	1 u + 11	36
Comparing between Cindy and Abi in the end	7 p	3 p	4 p

Difference between the number of paper balls that Cindy and Abi folded in the end is repeated.

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

Difference between the number of paper balls that Cindy and Abi folded in the end
= (1 u + 47) - (1 u + 11)
= 1 u + 47 - 1 u - 11
= 47 - 11
= 36

4 p = 36

1 p = 36 ÷ 4 = 9

Number of paper balls that Abi folded
= 3 p
= 3 x 9
= 27

Answer(s): 27