The ratio of the number of red stickers to blue stickers is 9 : 5.
After Adam buys another 40 red stickers and 70 blue stickers,
the ratio becomes of the number of red stickers to blue stickers is 5 : 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 5 = (4) |
Before |
27 u |
9 u |
5 u |
25 u |
Change |
+ 120 |
+ 40 |
+ 70 |
+ 350 |
After |
27 u + 120 |
9 u + 40 |
5 u + 70 |
25 u + 350 |
Comparing the red stickers and the blue stickers in the end |
15 p |
5 p |
3 p |
15 p |
9 u + 40 = 5 p --- (1)
5 u + 70 = 3 p --- (2)
Make p the same by using the LCM of 3 and 5.
LCM of 3 and 5 is 15.
(1)
x 3 27 u + 120 = 15 p --- (3)
(2)
x 5 25 u + 350 = 15 p --- (4)
(3) = (4)
27 u + 120 = 25 u + 350
27 u - 25 u = 350 - 120
2 u = 230
1 u = 230 ÷ 2 = 115
Number of stickers that Adam has now
= 9 u + 40 + 5 u + 70
= 9 u + 5 u + 40 + 70
= 14 u + 110
= 14 x 115 + 110
= 1610 + 110
= 1720
Answer(s): 1720