Tom, Flynn and Vaidev had the same number of marbles. Vaidev gave 0.6 of his marbles to Flynn. Then Flynn gave 0.25 of his marbles to Tom. Finally, after Flynn gave 36 marbles to Vaidev, he had the same number of marbles as Vaidev. How many marbles did Vaidev have at first?
| |
Tom |
Flynn |
Vaidev |
| Before |
1 u |
1 u |
1 u |
| Change 1 |
|
+ 0.6 u |
- 0.6 u |
| After 1 |
1 u |
1.6 u |
0.4 u |
| Change 2 |
+ 0.4 u |
- 0.4 u |
|
| After 2 |
1.4 u |
1.2 u |
0.4 u |
| Change 3 |
|
- 36 |
+ 36 |
| After 3 |
1.4 u |
1.2 u - 36 |
0.4 u + 36 |
Number of marbles that Flynn gave to Tom
= 0.25 x 1.6 u
= 0.4 u
The number of marbles that Flynn and Vaidev had in the end is the same.
1.2 u - 36 = 0.4 u + 36
1.2 u - 0.4 u = 36 + 36
0.8 u = 72
1 u = 72 ÷ 0.8 = 90
Number of marbles that Vaidev had at first
= 1 u
= 90
Answer(s): 90
