Adam has 50 red marbles and 150 green marbles.
After buying the same number of marbles,
the ratio of the red marbles and the green marbles becomes 3 : 5.
How many marbles does he buy?
|
Red |
Green |
Difference |
Before |
50 |
150 |
100 |
Change |
+ ? |
+ ? |
|
After |
3 u |
5 u |
2 u |
At first
Difference in the number of marbles
= 150 - 50
= 100
In the end
Number of red marbles = 3 u
Number of green marbles = 5 u
Difference in the number of marbles in units
= 5 u - 3 u
= 2 u
The difference in the number of marbles between the red marbles and the green marbles remains unchanged.
2 u = 100
1 u = 100 ÷ 2 = 50
Number of red marbles that Adam buys
= 3 u - 50
= 3 x 50 - 50
= 150 - 50
= 100
Total number of marbles that Adam buys
= 2 x 100
= 200
Answer(s): 200