The ratio of the number of red stickers to blue stickers is 4 : 1.
After Adam buys another 37 blue stickers and gives away 32 red stickers,
the ratio becomes of the number of red stickers to blue stickers is 7 : 4.
How many stickers does Adam have now?
|
Make p the same (1) x 4 = (3) |
(1) Red |
(2) Blue |
Make p the same (2) x 7 = (4) |
Before |
16 u |
4 u |
1 u |
7 u |
Change |
- 128 |
- 32 |
+ 37 |
+ 259 |
After |
28 p |
7 p |
4 p |
28 p |
4 u + 37 = 7 p --- (1)
1 u - 32 = 4 p --- (2)
Make p the same.
(1)
x 416 u - 128 = 28 p --- (3)
(2)
x 77 u + 259 = 28 p --- (4)
(3) = (4)
16 u - 128 = 7 u + 259
16 u - 7 u = 128 + 259
9 u = 387
1 u = 387 ÷ 9 = 43
Number of stickers that Adam have now
= 4 u + 37 + 1 u - 32
= 4 u + 1 u + 37 - 32
= 5 u + 5
= 5 x 43 + 5
= 215 + 5
= 220
Answer(s): 220