### 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-

A. 0.16 B. 0.172 C. 0.80 D. 0.87 Answer: Option A

### Solution(By Apex Team)

Number of units of work completed by the five workers in 1 minute: \begin{aligned}&A\rightarrow\frac{1}{4}\\ &B\rightarrow\frac{1}{5}\\ &C\rightarrow\frac{1}{6}\\ &D\rightarrow\frac{1}{10}\\ &E\rightarrow\frac{1}{12}\\ &\therefore\text{ Required average }\\ &=\frac{\left(\frac{1}{4}+\frac{1}{5}+\frac{1}{6}+\frac{1}{10}+\frac{1}{12}\right)}{5}\\ &=\left(\frac{4}{5}\times\frac{1}{5}\right)\\ &=\frac{4}{25}\\ &=0.16\end{aligned}

A. 20
B. 21
C. 28
D. 32

A. 18
B. 20
C. 24
D. 30

A. 10 years
B. 10.5 years
C. 11 years
D. 12 years