Ben and Harry had an equal number of books. Ben donated
17 of her books and Harry donated
14 of his books. Harry donated 9 more books than Ben. How many books did Harry have at first?
|
Ben |
Harry |
Before
|
7x4 = 28 u |
4x7 = 28 u |
Change
|
- 1x4 = - 4 u |
- 1x7 = - 7 u |
After
|
6x4 = 24 u |
3x7 = 21 u |
The number of books that Ben and Harry each had at first is the same. Make the number of books that Ben and Harry had at first the same. LCM of 7 and 4 is 28.
Number of books that Harry donated more than Ben
= 7 u - 4 u
= 3 u
3 u = 9
1 u = 9 ÷ 3 = 3
Number of books that Harry had
= 28 u
= 28 x 3
= 84
Answer(s): 84