Ian and Lee had an equal number of books. Ian donated
19 of her books and Lee donated
15 of his books. Lee donated 20 more books than Ian. How many books did Lee have at first?
| |
Ian |
Lee |
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 Ian and Lee each had at first is the same. Make the number of books that Ian and Lee had at first the same. LCM of 9 and 5 is 45.
Number of books that Lee donated more than Ian
= 9 u - 5 u
= 4 u
4 u = 20
1 u = 20 ÷ 4 = 5
Number of books that Lee had
= 45 u
= 45 x 5
= 225
Answer(s): 225
