Adam has 30 red beads and 180 green beads.
After buying the same number of beads,
the ratio of the red beads and the green beads becomes 3 : 5.
How many beads does he buy?
|
Red |
Green |
Difference |
Before |
30 |
180 |
150 |
Change |
+ ? |
+ ? |
|
After |
3 u |
5 u |
2 u |
At first
Difference in the number of beads
= 180 - 30
= 150
In the end
Number of red beads = 3 u
Number of green beads = 5 u
Difference in the number of beads in units
= 5 u - 3 u
= 2 u
The difference in the number of beads between the red beads and the green beads remains unchanged.
2 u = 150
1 u = 150 ÷ 2 = 75
Number of red beads that Adam buys
= 3 u - 30
= 3 x 75 - 30
= 225 - 30
= 195
Total number of beads that Adam buys
= 2 x 195
= 390
Answer(s): 390