John and Warren had an equal number of books. John donated
17 of her books and Warren donated
13 of his books. Warren donated 12 more books than John. How many books did Warren have at first?
| |
John |
Warren |
Before
|
7x3 =
21 u |
3x7 =
21 u |
Change
|
- 1x3 =
- 3 u |
- 1x7 =
- 7 u |
After
|
6x3 =
18 u |
2x7 =
14 u |
The number of books that John and Warren each had at first is the same. Make the number of books that John and Warren had at first the same. LCM of 7 and 3 is 21.
Number of books that Warren donated more than John
= 7 u - 3 u
= 4 u
4 u = 12
1 u = 12 ÷ 4 = 3
Number of books that Warren had
= 21 u
= 21 x 3
= 63
Answer(s): 63
