The ratio of the number of red stickers to blue stickers is 8 : 5.
After Adam buys another 10 red stickers and 70 blue stickers,
the ratio becomes of the number of red stickers to blue stickers is 6 : 5.
How many stickers does Adam have now?
|
Make p the same (1) x 5 = (3) |
(1) Red |
(2) Blue |
Make p the same (2) x 6 = (4) |
Before |
40 u |
8 u |
5 u |
30 u |
Change |
+ 50 |
+ 10 |
+ 70 |
+ 420 |
After |
40 u + 50 |
8 u + 10 |
5 u + 70 |
30 u + 420 |
Comparing the red stickers and the blue stickers in the end |
30 p |
6 p |
5 p |
30 p |
8 u + 10 = 6 p --- (1)
5 u + 70 = 5 p --- (2)
Make p the same by using the LCM of 5 and 6.
LCM of 5 and 6 is 30.
(1)
x 5 40 u + 50 = 30 p --- (3)
(2)
x 6 30 u + 420 = 30 p --- (4)
(3) = (4)
40 u + 50 = 30 u + 420
40 u - 30 u = 420 - 50
10 u = 370
1 u = 370 ÷ 10 = 37
Number of stickers that Adam has now
= 8 u + 10 + 5 u + 70
= 8 u + 5 u + 10 + 70
= 13 u + 80
= 13 x 37 + 80
= 481 + 80
= 561
Answer(s): 561