The ratio of the number of green stickers to blue stickers is 7 : 3.
After Adam buys another 33 blue stickers and gives away 31 green stickers,
the ratio becomes of the number of green stickers to blue stickers is 4 : 3.
How many stickers does Adam have now?
|
Make p the same (1) x 3 = (3) |
(1) Green |
(2) Blue |
Make p the same (2) x 4 = (4) |
Before |
21 u |
7 u |
3 u |
12 u |
Change |
- 93 |
- 31 |
+ 33 |
+ 132 |
After |
12 p |
4 p |
3 p |
12 p |
7 u + 33 = 4 p --- (1)
3 u - 31 = 3 p --- (2)
Make p the same.
(1)
x 321 u - 93 = 12 p --- (3)
(2)
x 412 u + 132 = 12 p --- (4)
(3) = (4)
21 u - 93 = 12 u + 132
21 u - 12 u = 93 + 132
9 u = 225
1 u = 225 ÷ 9 = 25
Number of stickers that Adam have now
= 7 u + 33 + 3 u - 31
= 7 u + 3 u + 33 - 31
= 10 u + 2
= 10 x 25 + 2
= 250 + 2
= 252
Answer(s): 252