The ratio of the number of blue stickers to red stickers is 5 : 4.
After Adam buys another 40 blue stickers and 50 red stickers,
the ratio becomes of the number of blue stickers to red stickers is 8 : 7.
How many stickers does Adam have now?
|
Make p the same (1) x 7 = (3) |
(1) Blue |
(2) Red |
Make p the same (2) x 8 = (4) |
Before |
35 u |
5 u |
4 u |
32 u |
Change |
+ 280 |
+ 40 |
+ 50 |
+ 400 |
After |
35 u + 280 |
5 u + 40 |
4 u + 50 |
32 u + 400 |
Comparing the blue stickers and the red stickers in the end |
56 p |
8 p |
7 p |
56 p |
5 u + 40 = 8 p --- (1)
4 u + 50 = 7 p --- (2)
Make p the same by using the LCM of 7 and 8.
LCM of 7 and 8 is 56.
(1)
x 7 35 u + 280 = 56 p --- (3)
(2)
x 8 32 u + 400 = 56 p --- (4)
(3) = (4)
35 u + 280 = 32 u + 400
35 u - 32 u = 400 - 280
3 u = 120
1 u = 120 ÷ 3 = 40
Number of stickers that Adam has now
= 5 u + 40 + 4 u + 50
= 5 u + 4 u + 40 + 50
= 9 u + 90
= 9 x 40 + 90
= 360 + 90
= 450
Answer(s): 450