The ratio of the number of blue stickers to red stickers is 3 : 2.
After Adam buys another 46 red stickers and gives away 15 blue stickers,
the ratio becomes of the number of blue stickers to red stickers is 5 : 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 5 = (4) |
Before |
12 u |
3 u |
2 u |
10 u |
Change |
- 60 |
- 15 |
+ 46 |
+ 230 |
After |
20 p |
5 p |
4 p |
20 p |
3 u + 46 = 5 p --- (1)
2 u - 15 = 4 p --- (2)
Make p the same.
(1)
x 412 u - 60 = 20 p --- (3)
(2)
x 510 u + 230 = 20 p --- (4)
(3) = (4)
12 u - 60 = 10 u + 230
12 u - 10 u = 60 + 230
2 u = 290
1 u = 290 ÷ 2 = 145
Number of stickers that Adam have now
= 3 u + 46 + 2 u - 15
= 3 u + 2 u + 46 - 15
= 5 u + 31
= 5 x 145 + 31
= 725 + 31
= 756
Answer(s): 756