Mrs Hun had a total of 108 white and pink lilies in the ratio of 7 : 5. After she had given away 3 times as many white lilies as pink lilies, the number of white and pink lilies left was in the ratio of 6 : 5. How many more white lilies than pink lilies did she give away?

	White	Pink	Total
Before	7 b	5 b	12 b
Change	- 3 u	- 1 u
After	6 p	5 p

	Make p the same (1)x5 = (3)	White (1)	Pink (2)	Make p the same (2)x6 = (4)
Before	315	63	45	270
Change	- 15 u	- 3 u	- 1 u	- 6 u
After	30 p	6 p	5 p	30 p

Number of lilies at first
= 7 b + 5 b
= 12 b

12 b = 108

1 b = 108 ÷ 12 = 9

Number of white lilies at first
= 7 b
= 7 x 9
= 63

Number of pink lilies at first
= 5 b
= 5 x 9
= 45

63 - 3 u = 6 p --- (1)

45 - 1 u = 5 p --- (2)

Make p the same.

(1)_x5 
315 - 15 u = 30 p --- (3)

(2)_x6 = (4)
270 - 6 u = 30 p --- (4)

(3) = (4)
315 - 15 u = 270 - 6 u
15 u - 6 u = 315 - 270
9 u = 45

1 u = 45 ÷ 9 = 5

Number of more white lilies than pink lilies that she gave away
= 3 u - 1 u
= 2 u
= 2 x 5
= 10

Answer(s): 10