11 Views

Question : A, B and C can do a piece of work in 11 days, 20 days and 55 days respectively. How soon can the work be done if A works with B on the first day, A works with C on the second day and so on?

Option 1: $8 \frac{1}{2}$ days

Option 2: $9\frac{1}{2}$ days

Option 3: 8 days

Option 4: 9 days


Team Careers360 23rd Jan, 2024
Answer (1)
Team Careers360 25th Jan, 2024

Correct Answer: 8 days


Solution : Total work = LCM (11, 20 and 55) = 220 units
Efficiency of A = $\frac{220}{11}$ = 20 units/day
Efficiency of B = $\frac{220}{20}$ = 11 units/day
Efficiency of C = $\frac{220}{55}$ = 4 units/day
Combined work of A and B = 20 + 11 = 31 units
Now A and C work together = 20 + 4 = 24 units
2 days' work = 31 + 24 = 55 units
We know, total work = 220 units
$\therefore$ Time taken = $2\times\frac{220}{55}=2\times4= 8$ days
Hence, the correct answer is 8 days.

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