The ratio of the number of green stickers to red stickers is 3 : 1.
After Adam buys another 60 green stickers and 70 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 |
9 u |
3 u |
1 u |
4 u |
Change |
+ 180 |
+ 60 |
+ 70 |
+ 280 |
After |
9 u + 180 |
3 u + 60 |
1 u + 70 |
4 u + 280 |
Comparing the green stickers and the red stickers in the end |
12 p |
4 p |
3 p |
12 p |
3 u + 60 = 4 p --- (1)
1 u + 70 = 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 9 u + 180 = 12 p --- (3)
(2)
x 4 4 u + 280 = 12 p --- (4)
(3) = (4)
9 u + 180 = 4 u + 280
9 u - 4 u = 280 - 180
5 u = 100
1 u = 100 ÷ 5 = 20
Number of stickers that Adam has now
= 3 u + 60 + 1 u + 70
= 3 u + 1 u + 60 + 70
= 4 u + 130
= 4 x 20 + 130
= 80 + 130
= 210
Answer(s): 210