John and Luke had an equal number of books. John donated
19 of her books and Luke donated
15 of his books. Luke donated 24 more books than John. How many books did Luke have at first?
| |
John |
Luke |
Before
|
9x5 =
45 u |
5x9 =
45 u |
Change
|
- 1x5 =
- 5 u |
- 1x9 =
- 9 u |
After
|
8x5 =
40 u |
4x9 =
36 u |
The number of books that John and Luke each had at first is the same. Make the number of books that John and Luke had at first the same. LCM of 9 and 5 is 45.
Number of books that Luke donated more than John
= 9 u - 5 u
= 4 u
4 u = 24
1 u = 24 ÷ 4 = 6
Number of books that Luke had
= 45 u
= 45 x 6
= 270
Answer(s): 270
