Mrs Ng had a total of 84 pink and yellow tulips in the ratio of 5 : 2. After she had given away 6 times as many pink tulips as yellow tulips, the number of pink and yellow tulips left was in the ratio of 4 : 3. How many more pink tulips than yellow tulips did she give away?
|
Pink |
Yellow |
Total |
Before |
5 b |
2 b |
7 b |
Change |
- 6 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 |
180 |
60 |
24 |
96 |
Change |
- 18 u |
- 6 u |
- 1 u |
- 4 u |
After |
12 p |
4 p |
3 p |
12 p |
Number of tulips at first
= 5 b + 2 b
= 7 b
7 b = 84
1 b = 84 ÷ 7 = 12
Number of pink tulips at first
= 5 b
= 5 x 12
= 60
Number of yellow tulips at first
= 2 b
= 2 x 12
= 24
60 - 6 u = 4 p --- (1)
24 - 1 u = 3 p --- (2)
Make p the same.
(1)
x3 180 - 18 u =
12 p --- (3)
(2)
x4 = (4)
96 - 4 u =
12 p --- (4)
(3) = (4)
180 - 18 u = 96 - 4 u
18 u - 4 u = 180 - 96
14 u = 84
1 u = 84 ÷ 14 = 6
Number of more pink tulips than yellow tulips that she gave away
= 6 u - 1 u
= 5 u
= 5 x 6
= 30
Answer(s): 30