Ravi and Kumar are working on a n assignment. Ravi takes 6 hours to type 32 pages on a computer, while Kumar takes 5 hours to type 40 pages. How much time will they take, working together on two different computers to type an assignment of 110 pages?

Correct option is B

​Given:

Ravi: 6 hours for 32 pages, ​​

Kumar: 5 hours for 40 pages, ​​

Formula Used:

​$$\text{Time} = \frac{\text{Total Pages}}{\text{Combined Rate}} \\ \ \\ \text{where, Combined Rate} = \text{Rate of Ravi} + \text{Rate of Kumar}.$$​​

Solution: 

Work rate of Ravi  =$$\frac{32}{6} \, \text{pages/hour} = 5.33 \, \text{pages/hour}.$$ 

Work rate of Kumar  =$$\frac{40}{5} \, \text{pages/hour} = 8 \, \text{pages/hour}.$$

​$$\text{Combined Rate} = 5.33 + 8 = 13.33 \, \text{pages/hour}$$​​

​$$\text{Time} = \frac{110}{13.33} \approx 8.25 \, \text{hours} \, (\text{or } 8 \, \text{hours and } 15 \, \text{minutes}).$$​​