The ratio of the number of blue stickers to red stickers is 3 : 1.
After Adam buys another 49 red stickers and gives away 23 blue stickers,
the ratio becomes of the number of blue stickers to red stickers is 7 : 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 7 = (4) |
Before |
12 u |
3 u |
1 u |
7 u |
Change |
- 92 |
- 23 |
+ 49 |
+ 343 |
After |
28 p |
7 p |
4 p |
28 p |
3 u + 49 = 7 p --- (1)
1 u - 23 = 4 p --- (2)
Make p the same.
(1)
x 412 u - 92 = 28 p --- (3)
(2)
x 77 u + 343 = 28 p --- (4)
(3) = (4)
12 u - 92 = 7 u + 343
12 u - 7 u = 92 + 343
5 u = 435
1 u = 435 ÷ 5 = 87
Number of stickers that Adam have now
= 3 u + 49 + 1 u - 23
= 3 u + 1 u + 49 - 23
= 4 u + 26
= 4 x 87 + 26
= 348 + 26
= 374
Answer(s): 374