The ratio of the number of red stickers to blue stickers is 3 : 2.
After Adam buys another 28 blue stickers and gives away 26 red stickers,
the ratio becomes of the number of red stickers to blue stickers is 5 : 4.
How many stickers does Adam have now?
|
Make p the same (1) x 4 = (3) |
(1) Red |
(2) Blue |
Make p the same (2) x 5 = (4) |
Before |
12 u |
3 u |
2 u |
10 u |
Change |
- 104 |
- 26 |
+ 28 |
+ 140 |
After |
20 p |
5 p |
4 p |
20 p |
3 u + 28 = 5 p --- (1)
2 u - 26 = 4 p --- (2)
Make p the same.
(1)
x 412 u - 104 = 20 p --- (3)
(2)
x 510 u + 140 = 20 p --- (4)
(3) = (4)
12 u - 104 = 10 u + 140
12 u - 10 u = 104 + 140
2 u = 244
1 u = 244 ÷ 2 = 122
Number of stickers that Adam have now
= 3 u + 28 + 2 u - 26
= 3 u + 2 u + 28 - 26
= 5 u + 2
= 5 x 122 + 2
= 610 + 2
= 612
Answer(s): 612