Bobby had 3 times as many books as Peter. After Bobby and Peter donated 53 books and 13 books away respectively, they were left with an equal number of books. How many books did Bobby have at first?
| |
Bobby |
Peter |
| Before |
3 u |
1 u |
| Change |
- 53 |
- 13 |
| After |
3 u - 53 |
1 u - 13 |
Bobby and Peter had the same number of books left.
3 u - 53 = 1 u - 13
3 u - 1 u = 53 - 13
2 u = 40
1 u = 40 ÷ 2 = 20
Number of books that Bobby had at first
= 3 u
= 3 x 20
= 60
Answer(s): 60
