Cody and Seth had an equal number of books. Cody donated
19 of her books and Seth donated
13 of his books. Seth donated 12 more books than Cody. How many books did Seth have at first?
| |
Cody |
Seth |
Before
|
9x1 =
9 u |
3x3 =
9 u |
Change
|
- 1x1 =
- 1 u |
- 1x3 =
- 3 u |
After
|
8x1 =
8 u |
2x3 =
6 u |
The number of books that Cody and Seth each had at first is the same. Make the number of books that Cody and Seth had at first the same. LCM of 9 and 3 is 9.
Number of books that Seth donated more than Cody
= 3 u - 1 u
= 2 u
2 u = 12
1 u = 12 ÷ 2 = 6
Number of books that Seth had
= 9 u
= 9 x 6
= 54
Answer(s): 54
