The ratio of the number of green stickers to red stickers is 3 : 1.
After Adam buys another 30 green stickers and 50 red stickers,
the ratio becomes of the number of green stickers to red stickers is 7 : 4.
How many stickers does Adam have now?
|
Make p the same (1) x 4 = (3) |
(1) Green |
(2) Red |
Make p the same (2) x 7 = (4) |
Before |
12 u |
3 u |
1 u |
7 u |
Change |
+ 120 |
+ 30 |
+ 50 |
+ 350 |
After |
12 u + 120 |
3 u + 30 |
1 u + 50 |
7 u + 350 |
Comparing the green stickers and the red stickers in the end |
28 p |
7 p |
4 p |
28 p |
3 u + 30 = 7 p --- (1)
1 u + 50 = 4 p --- (2)
Make p the same by using the LCM of 4 and 7.
LCM of 4 and 7 is 28.
(1)
x 4 12 u + 120 = 28 p --- (3)
(2)
x 7 7 u + 350 = 28 p --- (4)
(3) = (4)
12 u + 120 = 7 u + 350
12 u - 7 u = 350 - 120
5 u = 230
1 u = 230 ÷ 5 = 46
Number of stickers that Adam has now
= 3 u + 30 + 1 u + 50
= 3 u + 1 u + 30 + 50
= 4 u + 80
= 4 x 46 + 80
= 184 + 80
= 264
Answer(s): 264