Xavier, Zeph and George had the same number of marbles. George gave 0.6 of his marbles to Zeph. Then Zeph gave 0.25 of his marbles to Xavier. Finally, after Zeph gave 30 marbles to George, he had the same number of marbles as George. How many marbles did George have at first?
| |
Xavier |
Zeph |
George |
| 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 |
|
- 30 |
+ 30 |
| After 3 |
1.4 u |
1.2 u - 30 |
0.4 u + 30 |
Number of marbles that Zeph gave to Xavier
= 0.25 x 1.6 u
= 0.4 u
The number of marbles that Zeph and George had in the end is the same.
1.2 u - 30 = 0.4 u + 30
1.2 u - 0.4 u = 30 + 30
0.8 u = 60
1 u = 60 ÷ 0.8 = 75
Number of marbles that George had at first
= 1 u
= 75
Answer(s): 75
