The ratio of the number of green stickers to blue stickers is 5 : 3.
After Adam buys another 42 blue stickers and gives away 41 green stickers,
the ratio becomes of the number of green stickers to blue stickers is 4 : 3.
How many stickers does Adam have now?
|
Make p the same (1) x 3 = (3) |
(1) Green |
(2) Blue |
Make p the same (2) x 4 = (4) |
Before |
15 u |
5 u |
3 u |
12 u |
Change |
- 123 |
- 41 |
+ 42 |
+ 168 |
After |
12 p |
4 p |
3 p |
12 p |
5 u + 42 = 4 p --- (1)
3 u - 41 = 3 p --- (2)
Make p the same.
(1)
x 315 u - 123 = 12 p --- (3)
(2)
x 412 u + 168 = 12 p --- (4)
(3) = (4)
15 u - 123 = 12 u + 168
15 u - 12 u = 123 + 168
3 u = 291
1 u = 291 ÷ 3 = 97
Number of stickers that Adam have now
= 5 u + 42 + 3 u - 41
= 5 u + 3 u + 42 - 41
= 8 u + 1
= 8 x 97 + 1
= 776 + 1
= 777
Answer(s): 777