Question

Sita can finish typing a 100 page document in 9 hours, Mita in 6 hours and Rita in 12 hours. How long will they take to type a 100 page document if they work together?

Answer 1

Work done by Sita in 1 hour \(=\frac{1}{9}\)

Work done by Mita in 1 hour \(=\frac{1}{6}\)

 Work done by Rita in 1 hour \(=\frac{1}{12}\)

Work done by them together in 1 hour \(=\frac{1}{9}+\frac{1}{6}+\frac{1}{12}=\frac{4+6+3}{36}=\frac{13}{36}\)

∴ Time taken by them to complete the work together\(=\frac{1}{\frac{12}{36}}=\frac{36}{13}\) hours