The ratio of the number of blue stickers to red stickers is 4 : 3.
After Adam gives away 40 blue stickers and gives away 41 red 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 |
16 u |
4 u |
3 u |
27 u |
Change |
- 160 |
- 40 |
- 41 |
- 369 |
After |
36 p |
9 p |
4 p |
36 p |
4 u - 40 = 9 p --- (1)
3 u - 41 = 4 p --- (2)
Make p the same.
(1) x 4
16 u - 160 = 36 p --- (3)
(2) x 9
27 u - 369 = 36 p --- (4)
(4) = (3)
27 u - 369 = 16 u - 160
27 u - 16 u = 369 - 160
11 u = 209
1 u = 209 ÷ 11 = 19
Number of stickers that Adam has now
= 4 u - 40 + 3 u - 41
= 7 u - 81
= 7 x 19 - 81
= 133 - 81
= 52
Answer(s): 52