Archie had 3 times as many books as Fred. After Archie and Fred donated 42 books and 18 books away respectively, they were left with an equal number of books. How many books did Archie have at first?
| |
Archie |
Fred |
| Before |
3 u |
1 u |
| Change |
- 42 |
- 18 |
| After |
3 u - 42 |
1 u - 18 |
Archie and Fred had the same number of books left.
3 u - 42 = 1 u - 18
3 u - 1 u = 42 - 18
2 u = 24
1 u = 24 ÷ 2 = 12
Number of books that Archie had at first
= 3 u
= 3 x 12
= 36
Answer(s): 36
