The ratio of the number of red stickers to blue stickers is 3 : 1.
After Adam buys another 10 red stickers and 90 blue stickers,
the ratio becomes of the number of red stickers to blue stickers is 4 : 3.
How many stickers does Adam have now?
|
Make p the same (1) x 3 = (3) |
(1) Red |
(2) Blue |
Make p the same (2) x 4 = (4) |
Before |
9 u |
3 u |
1 u |
4 u |
Change |
+ 30 |
+ 10 |
+ 90 |
+ 360 |
After |
9 u + 30 |
3 u + 10 |
1 u + 90 |
4 u + 360 |
Comparing the red stickers and the blue stickers in the end |
12 p |
4 p |
3 p |
12 p |
3 u + 10 = 4 p --- (1)
1 u + 90 = 3 p --- (2)
Make p the same by using the LCM of 3 and 4.
LCM of 3 and 4 is 12.
(1)
x 3 9 u + 30 = 12 p --- (3)
(2)
x 4 4 u + 360 = 12 p --- (4)
(3) = (4)
9 u + 30 = 4 u + 360
9 u - 4 u = 360 - 30
5 u = 330
1 u = 330 ÷ 5 = 66
Number of stickers that Adam has now
= 3 u + 10 + 1 u + 90
= 3 u + 1 u + 10 + 90
= 4 u + 100
= 4 x 66 + 100
= 264 + 100
= 364
Answer(s): 364