The ratio of the number of blue stickers to red stickers is 7 : 2.
After Adam buys another 50 red stickers and gives away 35 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 |
28 u |
7 u |
2 u |
18 u |
Change |
- 140 |
- 35 |
+ 50 |
+ 450 |
After |
36 p |
9 p |
4 p |
36 p |
7 u + 50 = 9 p --- (1)
2 u - 35 = 4 p --- (2)
Make p the same.
(1)
x 428 u - 140 = 36 p --- (3)
(2)
x 918 u + 450 = 36 p --- (4)
(3) = (4)
28 u - 140 = 18 u + 450
28 u - 18 u = 140 + 450
10 u = 590
1 u = 590 ÷ 10 = 59
Number of stickers that Adam have now
= 7 u + 50 + 2 u - 35
= 7 u + 2 u + 50 - 35
= 9 u + 15
= 9 x 59 + 15
= 531 + 15
= 546
Answer(s): 546