The ratio of the number of green stickers to blue stickers is 9 : 5.
After Adam buys another 20 green stickers and 90 blue stickers,
the ratio becomes of the number of green stickers to blue stickers is 7 : 5.
How many stickers does Adam have now?
|
Make p the same (1) x 5 = (3) |
(1) Green |
(2) Blue |
Make p the same (2) x 7 = (4) |
Before |
45 u |
9 u |
5 u |
35 u |
Change |
+ 100 |
+ 20 |
+ 90 |
+ 630 |
After |
45 u + 100 |
9 u + 20 |
5 u + 90 |
35 u + 630 |
Comparing the green stickers and the blue stickers in the end |
35 p |
7 p |
5 p |
35 p |
9 u + 20 = 7 p --- (1)
5 u + 90 = 5 p --- (2)
Make p the same by using the LCM of 5 and 7.
LCM of 5 and 7 is 35.
(1)
x 5 45 u + 100 = 35 p --- (3)
(2)
x 7 35 u + 630 = 35 p --- (4)
(3) = (4)
45 u + 100 = 35 u + 630
45 u - 35 u = 630 - 100
10 u = 530
1 u = 530 ÷ 10 = 53
Number of stickers that Adam has now
= 9 u + 20 + 5 u + 90
= 9 u + 5 u + 20 + 90
= 14 u + 110
= 14 x 53 + 110
= 742 + 110
= 852
Answer(s): 852