Perry and Glen had an equal number of books. Perry donated
19 of her books and Glen donated
17 of his books. Glen donated 10 more books than Perry. How many books did Glen have at first?
| |
Perry |
Glen |
Before
|
9x7 =
63 u |
7x9 =
63 u |
Change
|
- 1x7 =
- 7 u |
- 1x9 =
- 9 u |
After
|
8x7 =
56 u |
6x9 =
54 u |
The number of books that Perry and Glen each had at first is the same. Make the number of books that Perry and Glen had at first the same. LCM of 9 and 7 is 63.
Number of books that Glen donated more than Perry
= 9 u - 7 u
= 2 u
2 u = 10
1 u = 10 ÷ 2 = 5
Number of books that Glen had
= 63 u
= 63 x 5
= 315
Answer(s): 315
