David has 178 marbles and Nick has 454 marbles. How many marbles must Nick give to David so that David will have 124 less marbles than Nick?
|
David |
Nick |
Total |
Before |
178 |
454 |
632 |
Change |
+ ? |
- ? |
|
After |
1 u |
1 u + 124 |
632 |
The total number of marbles remains unchanged after Nick gives to David.
Total number of marbles
= 178 + 454
= 632
Total number of marbles in the end
= 1 u + 1 u + 124
= 2 u + 124
2 u + 124 = 632
2 u = 632 - 124
2 u = 508
1 u = 508 ÷ 2 = 254
Number of marbles that Nick must give to David
= 254 - 178
= 76
Answer(s): 76