PSLE
Diana and Zoe folded paper balls over two days. On Wednesday, Diana folded 32 paper balls more than Zoe. On Thursday, Diana folded another 28 paper balls and Zoe folded another 18. At the end of the two days, Diana made ⁵₇ of the total number of balls. What was the number of paper balls that Zoe folded?

	Diana	Zoe	Difference
Before	1 u + 32	1 u	32
Change	+ 28	+ 18
After	1 u + 60	1 u + 18	42
Comparing between Diana and Zoe in the end	5 p	2 p	3 p

Difference between the number of paper balls that Diana and Zoe folded in the end is repeated.

Difference between the number of paper balls that Diana and Zoe folded in the end
= 5 p - 2 p
= 3 p

Difference between the number of paper balls that Diana and Zoe folded in the end
= (1 u + 60) - (1 u + 18)
= 1 u + 60 - 1 u - 18
= 60 - 18
= 42

3 p = 42

1 p = 42 ÷ 3 = 14

Number of paper balls that Zoe folded
= 2 p
= 2 x 14
= 28

Answer(s): 28