Adam has 40 red beads and 270 green beads.
After buying the same number of beads,
the ratio of the red beads and the green beads becomes 2 : 7.
How many beads does he buy?
|
Red |
Green |
Difference |
Before |
40 |
270 |
230 |
Change |
+ ? |
+ ? |
|
After |
2 u |
7 u |
5 u |
At first
Difference in the number of beads
= 270 - 40
= 230
In the end
Number of red beads = 2 u
Number of green beads = 7 u
Difference in the number of beads in units
= 7 u - 2 u
= 5 u
The difference in the number of beads between the red beads and the green beads remains unchanged.
5 u = 230
1 u = 230 ÷ 5 = 46
Number of red beads that Adam buys
= 2 u - 40
= 2 x 46 - 40
= 92 - 40
= 52
Total number of beads that Adam buys
= 2 x 52
= 104
Answer(s): 104