PSLE
Yoko bought some candy canes and gave half of it to Tommy. Tommy bought some chocolate bars and gave half of it to Yoko. Yoko ate 4 chocolate bars and Tommy ate 27 candy canes. The ratio of Yoko's chocolate bars to candy canes became 1 : 6 and the ratio of Tommy's chocolate bars to candy canes became 1 : 3. How many candy canes did Yoko buy?

	Yoko		Tommy
	Chocolate bars	Candy canes	Chocolate bars	Candy canes
Before	1 u + 4	6 u	1 p	3 p + 27
Change	- 4			- 27
After	1 u	6 u	1 p	3 p

After Yoko gave half of the candy canes to Tommy and Tommy gave half of his chocolate bars to Yoko, Tommy and Yoko had same number of chocolate bars and candy canes before each ate some.

6 u = 3 p + 27 
6 u - 27 = 3 p --- (1)

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

Make p the same.

(2)_x3
3 u + 12 = 3 p --- (3)

(1) = (3)
6 u - 27 = 3 u + 12 
6 u - 3 u = 12 + 27
3 u = 39

1 u = 39 ÷ 3 = 13

Number of candy canes that Yoko bought
= 2 x 6 u
= 12 u
= 12 x 13
= 156

Answer(s): 156