Caden, Henry and Simon had the same number of marbles. Simon gave 0.8 of his marbles to Henry. Then Henry gave 0.25 of his marbles to Caden. Finally, after Henry gave 23 marbles to Simon, he had the same number of marbles as Simon. How many marbles did Simon have at first?
| |
Caden |
Henry |
Simon |
| 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 |
|
- 23 |
+ 23 |
| After 3 |
1.45 u |
1.35 u - 23 |
0.2 u + 23 |
Number of marbles that Henry gave to Caden
= 0.25 x 1.8 u
= 0.45 u
The number of marbles that Henry and Simon had in the end is the same.
1.35 u - 23 = 0.2 u + 23
1.35 u - 0.2 u = 23 + 23
1.15 u = 46
1 u = 46 ÷ 1.15 = 40
Number of marbles that Simon had at first
= 1 u
= 40
Answer(s): 40
