Oliver and Luis had a total of 120 buttons. Luis had half as many buttons as Oliver. How many buttons must Oliver give to Luis so they have an equal number of buttons?
|
Oliver |
Luis |
Total |
Before |
2 u |
1 u |
120 |
Change |
- ? |
+ ? |
|
After |
1 |
1 |
|
Total number of buttons at first = 3 u
1 u = 120 ÷ 3 = 40
Oliver and Luis have an equal number of buttons in the end.
Number of buttons that Luis has in the end
= 120 ÷ 2
= 60
Number of buttons that Oliver must give to Luis
= 60 - 40
= 20
Answer(s): 20