Some identical comics can be arranged in exactly 13 per row. If the same number of comics is arranged in rows of 9 comics each, there will be 5 more rows but short of 9 comics. How many comics are there altogether?
|
13 per row |
9 per row |
Number |
1 u |
1 u + 5 |
Value |
13 u |
9 |
Total value |
13 u |
9 u + 45 - 9 |
Number of rows if the comics are arranged in rows of 13 = 1 u
Number of rows if the comics are arranged in rows of 9 = 1 u + 5
Total number of comics if they are arranged in rows of 13
= 13 x 1 u
= 13 u
Total number of comics if they are arranged in rows of 9
= 9 x (1 u + 5) - 9
= 9 u + 45 - 9
= 9 u + 36
The total number of comics remains the same for both cases.
13 u = 9 u + 36
13 u - 9 u = 36
4 u = 36
1 u = 36 ÷ 4 = 9
Total number of comics
= 13 u
= 13 x 9
= 117
Answer(s): 117