Oscar and Sam had a total of 60 marbles. Sam had half as many marbles as Oscar. How many marbles must Oscar give to Sam so they have an equal number of marbles?
| |
Oscar |
Sam |
Total |
| Before |
2 u |
1 u |
60 |
| Change |
- ? |
+ ? |
|
| After |
1 |
1 |
|
Total number of marbles at first = 3 u
1 u = 60 ÷ 3 = 20
Oscar and Sam have an equal number of marbles in the end.
Number of marbles that Sam has in the end
= 60 ÷ 2
= 30
Number of marbles that Oscar must give to Sam
= 30 - 20
= 10
Answer(s): 10
