The ratio of the number of green stickers to red stickers is 2 : 1.
After Adam buys another 40 green stickers and 80 red stickers,
the ratio becomes of the number of green stickers to red stickers is 4 : 3.
How many stickers does Adam have now?
|
Make p the same (1) x 3 = (3) |
(1) Green |
(2) Red |
Make p the same (2) x 4 = (4) |
Before |
6 u |
2 u |
1 u |
4 u |
Change |
+ 120 |
+ 40 |
+ 80 |
+ 320 |
After |
6 u + 120 |
2 u + 40 |
1 u + 80 |
4 u + 320 |
Comparing the green stickers and the red stickers in the end |
12 p |
4 p |
3 p |
12 p |
2 u + 40 = 4 p --- (1)
1 u + 80 = 3 p --- (2)
Make p the same by using the LCM of 3 and 4.
LCM of 3 and 4 is 12.
(1)
x 3 6 u + 120 = 12 p --- (3)
(2)
x 4 4 u + 320 = 12 p --- (4)
(3) = (4)
6 u + 120 = 4 u + 320
6 u - 4 u = 320 - 120
2 u = 200
1 u = 200 ÷ 2 = 100
Number of stickers that Adam has now
= 2 u + 40 + 1 u + 80
= 2 u + 1 u + 40 + 80
= 3 u + 120
= 3 x 100 + 120
= 300 + 120
= 420
Answer(s): 420