In a certain factory there are five workers A, B, C, D and E. A can complete a work in 4 minutes, B in 5 minutes, C in 6 minutes, D in 10 minutes and E in 12 minutes. The average number of units of work completed per worker per minute will be-

Solution(By Examveda Team)

Number of units of work completed by the five workers in 1 minute:
$$\eqalign{ & A \to \frac{1}{4}, \cr & B \to \frac{1}{5}, \cr & C \to \frac{1}{6}, \cr & D \to \frac{1}{{10}}, \cr & E \to \frac{1}{{12}} \cr} $$
∴ Required average
$$\eqalign{ & = \frac{{\left( {\frac{1}{4} + \frac{1}{5} + \frac{1}{6} + \frac{1}{{10}} + \frac{1}{{12}}} \right)}}{5} \cr & = \left( {\frac{4}{5} \times \frac{1}{5}} \right) \cr & = \frac{4}{{25}} \cr & = 0.16 \cr} $$