PSLE
Risa bought some candy canes and gave half of it to Rael. Rael bought some jelly beans and gave half of it to Risa. Risa ate 4 jelly beans and Rael ate 25 candy canes. The ratio of Risa's jelly beans to candy canes became 1 : 5 and the ratio of Rael's jelly beans to candy canes became 1 : 2. How many candy canes did Risa buy?

	Risa		Rael
	Jelly beans	Candy canes	Jelly beans	Candy canes
Before	1 u + 4	5 u	1 p	2 p + 25
Change	- 4			- 25
After	1 u	5 u	1 p	2 p

After Risa gave half of the candy canes to Rael and Rael gave half of his jelly beans to Risa, Rael and Risa had same number of jelly beans and candy canes before each ate some.

5 u = 2 p + 25 
5 u - 25 = 2 p --- (1)

1 u + 4 = 1 p --- (2)

Make p the same.

(2)_x2
2 u + 8 = 2 p --- (3)

(1) = (3)
5 u - 25 = 2 u + 8 
5 u - 2 u = 8 + 25
3 u = 33

1 u = 33 ÷ 3 = 11

Number of candy canes that Risa bought
= 2 x 5 u
= 10 u
= 10 x 11
= 110

Answer(s): 110