The ratio of the number of blue stickers to green stickers is 9 : 5.
After Adam buys another 20 blue stickers and 60 green stickers,
the ratio becomes of the number of blue stickers to green stickers is 5 : 4.
How many stickers does Adam have now?
|
Make p the same (1) x 4 = (3) |
(1) Blue |
(2) Green |
Make p the same (2) x 5 = (4) |
Before |
36 u |
9 u |
5 u |
25 u |
Change |
+ 80 |
+ 20 |
+ 60 |
+ 300 |
After |
36 u + 80 |
9 u + 20 |
5 u + 60 |
25 u + 300 |
Comparing the blue stickers and the green stickers in the end |
20 p |
5 p |
4 p |
20 p |
9 u + 20 = 5 p --- (1)
5 u + 60 = 4 p --- (2)
Make p the same by using the LCM of 4 and 5.
LCM of 4 and 5 is 20.
(1)
x 4 36 u + 80 = 20 p --- (3)
(2)
x 5 25 u + 300 = 20 p --- (4)
(3) = (4)
36 u + 80 = 25 u + 300
36 u - 25 u = 300 - 80
11 u = 220
1 u = 220 ÷ 11 = 20
Number of stickers that Adam has now
= 9 u + 20 + 5 u + 60
= 9 u + 5 u + 20 + 60
= 14 u + 80
= 14 x 20 + 80
= 280 + 80
= 360
Answer(s): 360