The ratio of the number of green stickers to blue stickers is 8 : 3.
After Adam buys another 40 green stickers and 60 blue stickers,
the ratio becomes of the number of green stickers to blue stickers is 7 : 3.
How many stickers does Adam have now?
|
Make p the same (1) x 3 = (3) |
(1) Green |
(2) Blue |
Make p the same (2) x 7 = (4) |
Before |
24 u |
8 u |
3 u |
21 u |
Change |
+ 120 |
+ 40 |
+ 60 |
+ 420 |
After |
24 u + 120 |
8 u + 40 |
3 u + 60 |
21 u + 420 |
Comparing the green stickers and the blue stickers in the end |
21 p |
7 p |
3 p |
21 p |
8 u + 40 = 7 p --- (1)
3 u + 60 = 3 p --- (2)
Make p the same by using the LCM of 3 and 7.
LCM of 3 and 7 is 21.
(1)
x 3 24 u + 120 = 21 p --- (3)
(2)
x 7 21 u + 420 = 21 p --- (4)
(3) = (4)
24 u + 120 = 21 u + 420
24 u - 21 u = 420 - 120
3 u = 300
1 u = 300 ÷ 3 = 100
Number of stickers that Adam has now
= 8 u + 40 + 3 u + 60
= 8 u + 3 u + 40 + 60
= 11 u + 100
= 11 x 100 + 100
= 1100 + 100
= 1200
Answer(s): 1200