Mrs Goh had a total of 80 pink and yellow carnations in the ratio of 5 : 3. After she had given away 3 times as many pink carnations as yellow carnations, the number of pink and yellow carnations left was in the ratio of 4 : 3. How many more pink carnations than yellow carnations did she give away?

	Pink	Yellow	Total
Before	5 b	3 b	8 b
Change	- 3 u	- 1 u
After	4 p	3 p

	Make p the same (1)x3 = (3)	Pink (1)	Yellow (2)	Make p the same (2)x4 = (4)
Before	150	50	30	120
Change	- 9 u	- 3 u	- 1 u	- 4 u
After	12 p	4 p	3 p	12 p

Number of carnations at first
= 5 b + 3 b
= 8 b

8 b = 80

1 b = 80 ÷ 8 = 10

Number of pink carnations at first
= 5 b
= 5 x 10
= 50

Number of yellow carnations at first
= 3 b
= 3 x 10
= 30

50 - 3 u = 4 p --- (1)

30 - 1 u = 3 p --- (2)

Make p the same.

(1)_x3 
150 - 9 u = 12 p --- (3)

(2)_x4 = (4)
120 - 4 u = 12 p --- (4)

(3) = (4)
150 - 9 u = 120 - 4 u
9 u - 4 u = 150 - 120
5 u = 30

1 u = 30 ÷ 5 = 6

Number of more pink carnations than yellow carnations that she gave away
= 3 u - 1 u
= 2 u
= 2 x 6
= 12

Answer(s): 12