PSLE
Hilda bought some sweets and gave half of it to Flynn. Flynn bought some lollipops and gave half of it to Hilda. Hilda ate 4 lollipops and Flynn ate 24 sweets. The ratio of Hilda's lollipops to sweets became 1 : 6 and the ratio of Flynn's lollipops to sweets became 1 : 2. How many lollipops did Flynn buy?

	Hilda		Flynn
	Lollipops	Sweets	Lollipops	Sweets
Before	1 u + 4	6 u	1 p	2 p + 24
Change	- 4			- 24
After	1 u	6 u	1 p	2 p

After Hilda gave half of the sweets to Flynn and Flynn gave half of his lollipops to Hilda, Flynn and Hilda had same number of lollipops and sweets before each ate some.

6 u = 2 p + 24 
6 u - 24 = 2 p --- (1)

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

Make p the same.

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

(1) = (3)
6 u - 24 = 2 u + 8 
6 u - 2 u = 8 + 24
4 u = 32

1 u = 32 ÷ 4 = 8

1 p
= 1 u + 4
= 8 + 4
= 12

Number of lollipops that Flynn bought
= 2 p
= 2 x 12
= 24

Answer(s): 24