The ratio of the number of blue stickers to red stickers is 4 : 3.
After Adam gives away 85 blue stickers and gives away 99 red stickers,
the ratio becomes of the number of blue stickers to red stickers is 5 : 3.
How many stickers does Adam have now?
|
Make p the same (1) x 3 = (3) |
(1) Blue |
(2) Red |
Make p the same (2) x 5 = (4) |
Before |
12 u |
4 u |
3 u |
15 u |
Change |
- 255 |
- 85 |
- 99 |
- 495 |
After |
15 p |
5 p |
3 p |
15 p |
4 u - 85 = 5 p --- (1)
3 u - 99 = 3 p --- (2)
Make p the same.
(1) x 3
12 u - 255 = 15 p --- (3)
(2) x 5
15 u - 495 = 15 p --- (4)
(4) = (3)
15 u - 495 = 12 u - 255
15 u - 12 u = 495 - 255
3 u = 240
1 u = 240 ÷ 3 = 80
Number of stickers that Adam has now
= 4 u - 85 + 3 u - 99
= 7 u - 184
= 7 x 80 - 184
= 560 - 184
= 376
Answer(s): 376