The ratio of the number of red stickers to blue stickers is 3 : 2.
After Adam gives away 45 red stickers and gives away 44 blue stickers,
the ratio becomes of the number of red stickers to blue stickers is 7 : 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 7 = (4) |
Before |
12 u |
3 u |
2 u |
14 u |
Change |
- 180 |
- 45 |
- 44 |
- 308 |
After |
28 p |
7 p |
4 p |
28 p |
3 u - 45 = 7 p --- (1)
2 u - 44 = 4 p --- (2)
Make p the same.
(1) x 4
12 u - 180 = 28 p --- (3)
(2) x 7
14 u - 308 = 28 p --- (4)
(4) = (3)
14 u - 308 = 12 u - 180
14 u - 12 u = 308 - 180
2 u = 128
1 u = 128 ÷ 2 = 64
Number of stickers that Adam has now
= 3 u - 45 + 2 u - 44
= 5 u - 89
= 5 x 64 - 89
= 320 - 89
= 231
Answer(s): 231