Henry and Tom had an equal number of books. Henry donated
17 of her books and Tom donated
15 of his books. Tom donated 4 more books than Henry. How many books did Tom have at first?
| |
Henry |
Tom |
Before
|
7x5 =
35 u |
5x7 =
35 u |
Change
|
- 1x5 =
- 5 u |
- 1x7 =
- 7 u |
After
|
6x5 =
30 u |
4x7 =
28 u |
The number of books that Henry and Tom each had at first is the same. Make the number of books that Henry and Tom had at first the same. LCM of 7 and 5 is 35.
Number of books that Tom donated more than Henry
= 7 u - 5 u
= 2 u
2 u = 4
1 u = 4 ÷ 2 = 2
Number of books that Tom had
= 35 u
= 35 x 2
= 70
Answer(s): 70
