Jack, Wesley and David had the same number of beads. David gave 0.8 of his beads to Wesley. Then Wesley gave 0.25 of his beads to Jack. Finally, after Wesley gave 46 beads to David, he had the same number of beads as David. How many beads did David have at first?
| |
Jack |
Wesley |
David |
| Before |
1 u |
1 u |
1 u |
| Change 1 |
|
+ 0.8 u |
- 0.8 u |
| After 1 |
1 u |
1.8 u |
0.2 u |
| Change 2 |
+ 0.45 u |
- 0.45 u |
|
| After 2 |
1.45 u |
1.35 u |
0.2 u |
| Change 3 |
|
- 46 |
+ 46 |
| After 3 |
1.45 u |
1.35 u - 46 |
0.2 u + 46 |
Number of beads that Wesley gave to Jack
= 0.25 x 1.8 u
= 0.45 u
The number of beads that Wesley and David had in the end is the same.
1.35 u - 46 = 0.2 u + 46
1.35 u - 0.2 u = 46 + 46
1.15 u = 92
1 u = 92 ÷ 1.15 = 80
Number of beads that David had at first
= 1 u
= 80
Answer(s): 80
