The ratio of the number of blue stickers to green stickers is 4 : 3.
After Adam buys another 20 blue stickers and 70 green stickers,
the ratio becomes of the number of blue stickers to green stickers is 6 : 5.
How many stickers does Adam have now?
|
Make p the same (1) x 5 = (3) |
(1) Blue |
(2) Green |
Make p the same (2) x 6 = (4) |
Before |
20 u |
4 u |
3 u |
18 u |
Change |
+ 100 |
+ 20 |
+ 70 |
+ 420 |
After |
20 u + 100 |
4 u + 20 |
3 u + 70 |
18 u + 420 |
Comparing the blue stickers and the green stickers in the end |
30 p |
6 p |
5 p |
30 p |
4 u + 20 = 6 p --- (1)
3 u + 70 = 5 p --- (2)
Make p the same by using the LCM of 5 and 6.
LCM of 5 and 6 is 30.
(1)
x 5 20 u + 100 = 30 p --- (3)
(2)
x 6 18 u + 420 = 30 p --- (4)
(3) = (4)
20 u + 100 = 18 u + 420
20 u - 18 u = 420 - 100
2 u = 320
1 u = 320 ÷ 2 = 160
Number of stickers that Adam has now
= 4 u + 20 + 3 u + 70
= 4 u + 3 u + 20 + 70
= 7 u + 90
= 7 x 160 + 90
= 1120 + 90
= 1210
Answer(s): 1210