29 Views

Question : John can do a piece of work alone in 20 days, while Ravi can do the same piece of work alone in 28 days. In how many days can the duo complete the same work if they work together?

Option 1: $11 \frac{1}{3}$

Option 2: $12 \frac{2}{3}$

Option 3: $11 \frac{2}{3}$

Option 4: $12 \frac{1}{3}$


Team Careers360 7th Jan, 2024
Answer (1)
Team Careers360 17th Jan, 2024

Correct Answer: $11 \frac{2}{3}$


Solution : John can do a piece of work alone in = 20 days
Ravi can do the same piece of work alone in = 28 days
Efficiency of John = $\frac{1}{20}$
Efficiency of Ravi = $\frac{1}{28}$
Combine efficiency = $\frac{1}{20} + \frac{1}{28} = \frac{12}{140} = \frac{3}{35}$
Now, efficiency = $\frac{\text{Total work}}{\text{Time taken}}$
Days taken by duo to complete the same work if they work together = (1 ÷ $\frac{3}{35}$) = $\frac{35}{3} $ = $11\frac{2}{3}$ days
Hence, the correct answer is  $11\frac{2}{3}$.

Know More About

Related Questions

TOEFL ® Registrations 2024
Apply
Accepted by more than 11,000 universities in over 150 countries worldwide
Manipal Online M.Com Admissions
Apply
Apply for Online M.Com from Manipal University
View All Application Forms

Download the Careers360 App on your Android phone

Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile

150M+ Students
30,000+ Colleges
500+ Exams
1500+ E-books