Andy and Perry had an equal number of books. Andy donated
15 of her books and Perry donated
13 of his books. Perry donated 18 more books than Andy. How many books did Perry have at first?
| |
Andy |
Perry |
Before
|
5x3 =
15 u |
3x5 =
15 u |
Change
|
- 1x3 =
- 3 u |
- 1x5 =
- 5 u |
After
|
4x3 =
12 u |
2x5 =
10 u |
The number of books that Andy and Perry each had at first is the same. Make the number of books that Andy and Perry had at first the same. LCM of 5 and 3 is 15.
Number of books that Perry donated more than Andy
= 5 u - 3 u
= 2 u
2 u = 18
1 u = 18 ÷ 2 = 9
Number of books that Perry had
= 15 u
= 15 x 9
= 135
Answer(s): 135
