Oscar has 103 marbles and Jack has 436 marbles. How many marbles must Jack give to Oscar so that Oscar will have 123 less marbles than Jack?
| |
Oscar |
Jack |
Total |
| Before |
103 |
436 |
539 |
| Change |
+ ? |
- ? |
|
| After |
1 u |
1 u + 123 |
539 |
The total number of marbles remains unchanged after Jack gives to Oscar.
Total number of marbles
= 103 + 436
= 539
Total number of marbles in the end
= 1 u + 1 u + 123
= 2 u + 123
2 u + 123 = 539
2 u = 539 - 123
2 u = 416
1 u = 416 ÷ 2 = 208
Number of marbles that Jack must give to Oscar
= 208 - 103
= 105
Answer(s): 105
