The ratio of the number of blue stickers to red stickers is 5 : 1.
After Adam buys another 45 red stickers and gives away 17 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 |
20 u |
5 u |
1 u |
9 u |
Change |
- 68 |
- 17 |
+ 45 |
+ 405 |
After |
36 p |
9 p |
4 p |
36 p |
5 u + 45 = 9 p --- (1)
1 u - 17 = 4 p --- (2)
Make p the same.
(1)
x 420 u - 68 = 36 p --- (3)
(2)
x 99 u + 405 = 36 p --- (4)
(3) = (4)
20 u - 68 = 9 u + 405
20 u - 9 u = 68 + 405
11 u = 473
1 u = 473 ÷ 11 = 43
Number of stickers that Adam have now
= 5 u + 45 + 1 u - 17
= 5 u + 1 u + 45 - 17
= 6 u + 28
= 6 x 43 + 28
= 258 + 28
= 286
Answer(s): 286