The ratio of the number of green stickers to blue stickers is 7 : 4.
After Adam buys another 20 green stickers and 40 blue stickers,
the ratio becomes of the number of green stickers to blue stickers is 3 : 2.
How many stickers does Adam have now?
|
Make p the same (1) x 2 = (3) |
(1) Green |
(2) Blue |
Make p the same (2) x 3 = (4) |
Before |
14 u |
7 u |
4 u |
12 u |
Change |
+ 40 |
+ 20 |
+ 40 |
+ 120 |
After |
14 u + 40 |
7 u + 20 |
4 u + 40 |
12 u + 120 |
Comparing the green stickers and the blue stickers in the end |
6 p |
3 p |
2 p |
6 p |
7 u + 20 = 3 p --- (1)
4 u + 40 = 2 p --- (2)
Make p the same by using the LCM of 2 and 3.
LCM of 2 and 3 is 6.
(1)
x 2 14 u + 40 = 6 p --- (3)
(2)
x 3 12 u + 120 = 6 p --- (4)
(3) = (4)
14 u + 40 = 12 u + 120
14 u - 12 u = 120 - 40
2 u = 80
1 u = 80 ÷ 2 = 40
Number of stickers that Adam has now
= 7 u + 20 + 4 u + 40
= 7 u + 4 u + 20 + 40
= 11 u + 60
= 11 x 40 + 60
= 440 + 60
= 500
Answer(s): 500