Bobby and Ben had an equal number of books. Bobby donated
19 of her books and Ben donated
14 of his books. Ben donated 20 more books than Bobby. How many books did Ben have at first?
|
Bobby |
Ben |
Before
|
9x4 = 36 u |
4x9 = 36 u |
Change
|
- 1x4 = - 4 u |
- 1x9 = - 9 u |
After
|
8x4 = 32 u |
3x9 = 27 u |
The number of books that Bobby and Ben each had at first is the same. Make the number of books that Bobby and Ben had at first the same. LCM of 9 and 4 is 36.
Number of books that Ben donated more than Bobby
= 9 u - 4 u
= 5 u
5 u = 20
1 u = 20 ÷ 5 = 4
Number of books that Ben had
= 36 u
= 36 x 4
= 144
Answer(s): 144