PSLE
Emily and Eva folded paper balls over two days. On Thursday, Emily folded 31 paper balls more than Eva. On Friday, Emily folded another 32 paper balls and Eva folded another 8. At the end of the two days, Emily made ⁷₉ of the total number of balls. What was the number of paper balls that Emily folded?

	Emily	Eva	Difference
Before	1 u + 31	1 u	31
Change	+ 32	+ 8
After	1 u + 63	1 u + 8	55
Comparing between Emily and Eva in the end	7 p	2 p	5 p

Difference between the number of paper balls that Emily and Eva folded in the end is repeated.

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

Difference between the number of paper balls that Emily and Eva folded in the end
= (1 u + 63) - (1 u + 8)
= 1 u + 63 - 1 u - 8
= 63 - 8
= 55

5 p = 55

1 p = 55 ÷ 5 = 11

Number of paper balls that Emily folded
= 7 p
= 7 x 11
= 77

Answer(s): 77