Sean, Xavier and Ben had 48 marbles. After Sean used 2 marbles and Xavier used
12 of her marbles, Sean had twice as many marbles left as Xavier. Ben bought another 10 marbles, he had thrice the number of marbles Xavier had left. How many marbles did Ben have at first?
| |
Sean |
Xavier |
Ben |
Total |
| Before |
2 u + 2 |
2 u |
3 u - 10 |
48 |
| Change |
- 2 |
- 1 u |
+ 10 |
|
| After |
2 u |
1 u |
3 u |
|
Comparing Sean
and Xavier in the end |
2 |
1 |
|
|
Comparing Ben
and Xavier in the end |
|
1 |
3 |
|
Number of marbles that Sean had in the end
= 2 x 1 u
= 2 u
Number of marbles that Ben had in the end
= 3 x 1 u
= 3 u
Total number of marbles at first
= 2 u + 2 + 2 u + 3 u - 10
= 7 u - 8
7 u - 8 = 48
7 u = 48 + 8
7 u = 56
1 u = 56 ÷ 7 = 8
Number of marbles that Ben had at first
= 3 u - 10
= 3 x 8 - 10
= 24 - 10
= 14
Answer(s): 14
