The ratio of the number of blue stickers to red stickers is 8 : 3.
After Adam buys another 18 red stickers and gives away 12 blue stickers,
the ratio becomes of the number of blue stickers to red stickers is 9 : 4.
How many stickers does Adam have now?
|
Make p the same (1) x 4 = (3) |
(1) Blue |
(2) Red |
Make p the same (2) x 9 = (4) |
Before |
32 u |
8 u |
3 u |
27 u |
Change |
- 48 |
- 12 |
+ 18 |
+ 162 |
After |
36 p |
9 p |
4 p |
36 p |
8 u + 18 = 9 p --- (1)
3 u - 12 = 4 p --- (2)
Make p the same.
(1)
x 432 u - 48 = 36 p --- (3)
(2)
x 927 u + 162 = 36 p --- (4)
(3) = (4)
32 u - 48 = 27 u + 162
32 u - 27 u = 48 + 162
5 u = 210
1 u = 210 ÷ 5 = 42
Number of stickers that Adam have now
= 8 u + 18 + 3 u - 12
= 8 u + 3 u + 18 - 12
= 11 u + 6
= 11 x 42 + 6
= 462 + 6
= 468
Answer(s): 468