Question

12 typists working for 4 hours per day to type a book in 18 days. How many days will 4 typists have to work for 8 hours per day to type the same book?

• A. 25
• B. 26
• C. 27
• D. 30

Answer 1

The correct option is C

27

Number of days taken in typing a book by 12 typists working for 4 hours = 18 days

Number of days taken in typing a book by 1 typist working for 4 hours = 18 × 12 days

Number of days taken in typing a book by 1 typist working for 1 hour = 18 × 12 × 4 days

Number of days taken in typing a book by 4 typists working for 1 hour = $\frac{18\times 12\times 4}{4}$

Number of days taken in typing a book by 4 typists working for 8 hours = $\frac{18\times 12\times 4}{4\times 8}$ = 27 days

Therefore, 4 typists working for 8 hours type a book in 27 days.