Michael, Warren and Riordan had the same number of marbles. Riordan gave 0.6 of his marbles to Warren. Then Warren gave 0.35 of his marbles to Michael. Finally, after Warren gave 24 marbles to Riordan, he had the same number of marbles as Riordan. How many marbles did Riordan have at first?
| |
Michael |
Warren |
Riordan |
| 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 |
+ 0.56 u |
- 0.56 u |
|
| After 2 |
1.56 u |
1.04 u |
0.4 u |
| Change 3 |
|
- 24 |
+ 24 |
| After 3 |
1.56 u |
1.04 u - 24 |
0.4 u + 24 |
Number of marbles that Warren gave to Michael
= 0.35 x 1.6 u
= 0.56 u
The number of marbles that Warren and Riordan had in the end is the same.
1.04 u - 24 = 0.4 u + 24
1.04 u - 0.4 u = 24 + 24
0.64 u = 48
1 u = 48 ÷ 0.64 = 75
Number of marbles that Riordan had at first
= 1 u
= 75
Answer(s): 75
