The ratio of the number of blue stickers to green stickers is 2 : 1.
After Adam buys another 10 blue stickers and 20 green stickers,
the ratio becomes of the number of blue stickers to green stickers is 8 : 7.
How many stickers does Adam have now?
|
Make p the same (1) x 7 = (3) |
(1) Blue |
(2) Green |
Make p the same (2) x 8 = (4) |
Before |
14 u |
2 u |
1 u |
8 u |
Change |
+ 70 |
+ 10 |
+ 20 |
+ 160 |
After |
14 u + 70 |
2 u + 10 |
1 u + 20 |
8 u + 160 |
Comparing the blue stickers and the green stickers in the end |
56 p |
8 p |
7 p |
56 p |
2 u + 10 = 8 p --- (1)
1 u + 20 = 7 p --- (2)
Make p the same by using the LCM of 7 and 8.
LCM of 7 and 8 is 56.
(1)
x 7 14 u + 70 = 56 p --- (3)
(2)
x 8 8 u + 160 = 56 p --- (4)
(3) = (4)
14 u + 70 = 8 u + 160
14 u - 8 u = 160 - 70
6 u = 90
1 u = 90 ÷ 6 = 15
Number of stickers that Adam has now
= 2 u + 10 + 1 u + 20
= 2 u + 1 u + 10 + 20
= 3 u + 30
= 3 x 15 + 30
= 45 + 30
= 75
Answer(s): 75