The ratio of the number of blue stickers to red stickers is 8 : 1.
After Adam buys another 20 red stickers and gives away 16 blue 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 |
24 u |
8 u |
1 u |
8 u |
Change |
- 48 |
- 16 |
+ 20 |
+ 160 |
After |
24 p |
8 p |
3 p |
24 p |
8 u + 20 = 8 p --- (1)
1 u - 16 = 3 p --- (2)
Make p the same.
(1)
x 324 u - 48 = 24 p --- (3)
(2)
x 88 u + 160 = 24 p --- (4)
(3) = (4)
24 u - 48 = 8 u + 160
24 u - 8 u = 48 + 160
16 u = 208
1 u = 208 ÷ 16 = 13
Number of stickers that Adam have now
= 8 u + 20 + 1 u - 16
= 8 u + 1 u + 20 - 16
= 9 u + 4
= 9 x 13 + 4
= 117 + 4
= 121
Answer(s): 121