The ratio of the number of blue stickers to red stickers is 7 : 3.
After Adam gives away 52 blue stickers and gives away 42 red stickers,
the ratio becomes of the number of blue stickers to red stickers is 8 : 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 8 = (4) |
Before |
21 u |
7 u |
3 u |
24 u |
Change |
- 156 |
- 52 |
- 42 |
- 336 |
After |
24 p |
8 p |
3 p |
24 p |
7 u - 52 = 8 p --- (1)
3 u - 42 = 3 p --- (2)
Make p the same.
(1) x 3
21 u - 156 = 24 p --- (3)
(2) x 8
24 u - 336 = 24 p --- (4)
(4) = (3)
24 u - 336 = 21 u - 156
24 u - 21 u = 336 - 156
3 u = 180
1 u = 180 ÷ 3 = 60
Number of stickers that Adam has now
= 7 u - 52 + 3 u - 42
= 10 u - 94
= 10 x 60 - 94
= 600 - 94
= 506
Answer(s): 506