PSLE
Kathy and Cindy folded paper cranes over two days. On Friday, Kathy folded 45 paper cranes more than Cindy. On Saturday, Kathy folded another 21 paper cranes and Cindy folded another 6. At the end of the two days, Kathy made ⁷₉ of the total number of cranes. What was the number of paper cranes that Kathy folded?

	Kathy	Cindy	Difference
Before	1 u + 45	1 u	45
Change	+ 21	+ 6
After	1 u + 66	1 u + 6	60
Comparing between Kathy and Cindy in the end	7 p	2 p	5 p

Difference between the number of paper cranes that Kathy and Cindy folded in the end is repeated.

Difference between the number of paper cranes that Kathy and Cindy folded in the end
= 7 p - 2 p
= 5 p

Difference between the number of paper cranes that Kathy and Cindy folded in the end
= (1 u + 66) - (1 u + 6)
= 1 u + 66 - 1 u - 6
= 66 - 6
= 60

5 p = 60

1 p = 60 ÷ 5 = 12

Number of paper cranes that Kathy folded
= 7 p
= 7 x 12
= 84

Answer(s): 84