Some identical story books can be arranged in exactly 12 per row. If the same number of story books is arranged in rows of 8 story books each, there will be 5 more rows but short of 8 story books. How many story books are there altogether?
| |
12 per row |
8 per row |
| Number |
1 u |
1 u + 5 |
| Value |
12 u |
8 |
| Total value |
12 u |
8 u + 40 - 8 |
Number of rows if the story books are arranged in rows of 12 = 1 u
Number of rows if the story books are arranged in rows of 8 = 1 u + 5
Total number of story books if they are arranged in rows of 12
= 12 x 1 u
= 12 u
Total number of story books if they are arranged in rows of 8
= 8 x (1 u + 5) - 8
= 8 u + 40 - 8
= 8 u + 32
The total number of story books remains the same for both cases.
12 u = 8 u + 32
12 u - 8 u = 32
4 u = 32
1 u = 32 ÷ 4 = 8
Total number of story books
= 12 u
= 12 x 8
= 96
Answer(s): 96
