Seth and Ethan had an equal number of books. Seth donated
19 of her books and Ethan donated
13 of his books. Ethan donated 10 more books than Seth. How many books did Ethan have at first?
| |
Seth |
Ethan |
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 Seth and Ethan each had at first is the same. Make the number of books that Seth and Ethan had at first the same. LCM of 9 and 3 is 9.
Number of books that Ethan donated more than Seth
= 3 u - 1 u
= 2 u
2 u = 10
1 u = 10 ÷ 2 = 5
Number of books that Ethan had
= 9 u
= 9 x 5
= 45
Answer(s): 45
