2020 · Q17
A 60-page book has n lines per page. If the number of lines were reduced by 3 in each page, the number of pages would have to be increased by 10 to give the same writing space. What is the value of n?
Elementary MathematicsTime and Work
- A18
- B21
- C24
- D30
Explanation
Total lines are unchanged: 60n = 70(n-3), so 10n = 210 and n = 21. Hence option (B). Check: 60*21 = 1260 lines and 70*18 = 1260 lines - identical writing space.