David had
25 the number of erasers that Luke had at first. After Luke gave David 72 of his erasers, David had
47 the number of erasers that Luke had. How many erasers did Luke have in the end?
| |
David |
Luke |
Total |
| Before |
2x11 =
22 u |
5x11 =
55 u |
7x11 =
77 u |
| Change |
+ 6 u |
- 6 u |
|
| After |
4x7 =
28 u |
7x7 =
49 u |
11x7 =
77 u |
The total number of erasers that David and Luke had at first and in the end remains unchanged. Make the total number of erasers the same. LCM of 7 and 11 is 77.
Number of erasers that Luke gave David
= 28 u - 22 u
= 6 u
6 u = 72
1 u = 72 ÷ 6 = 12
Number of erasers that Luke had in the end
= 49 u
= 49 x 12
= 588
Answer(s): 588
