The ratio of the number of blue stickers to red stickers is 8 : 3.
After Adam gives away 54 blue stickers and gives away 19 red stickers,
the ratio becomes of the number of blue stickers to red stickers is 7 : 2.
How many stickers does Adam have now?
|
Make p the same (1) x 2 = (3) |
(1) Blue |
(2) Red |
Make p the same (2) x 7 = (4) |
Before |
16 u |
8 u |
3 u |
21 u |
Change |
- 108 |
- 54 |
- 19 |
- 133 |
After |
14 p |
7 p |
2 p |
14 p |
8 u - 54 = 7 p --- (1)
3 u - 19 = 2 p --- (2)
Make p the same.
(1) x 2
16 u - 108 = 14 p --- (3)
(2) x 7
21 u - 133 = 14 p --- (4)
(4) = (3)
21 u - 133 = 16 u - 108
21 u - 16 u = 133 - 108
5 u = 25
1 u = 25 ÷ 5 = 5
Number of stickers that Adam has now
= 8 u - 54 + 3 u - 19
= 11 u - 73
= 11 x 5 - 73
= 55 - 73
= -18
Answer(s): -18