1671 Views

P is twice as fast as Q and R together .Working together ,all three can do a work in 21 days.In how many days can Q and R together do the work


Simran 9th Jan, 2020
Answer (1)
KUNAL LANJEWAR 14th Jan, 2020

Hello,

Let, the work done by P be p

and the work done by Q and R together be x

So, from first condition, p = 2x

All three can do work in 21 days.

So, 21 [ ( 1 / 2x ) + ( 1 / x ) ] = 1

So, 21 ( 3x / 2 x^2 ) = 1

So, 2x = 3 x 21

So, x = 63 / 2

So, x = 31.5 days.

So, Q and R can do the work together in 31.5 days

Best Wishes.

Related Questions

Amity University-Noida B.Tech...
Apply
Among top 100 Universities Globally in the Times Higher Education (THE) Interdisciplinary Science Rankings 2026
VIT - VITEEE 2026
Apply
National level exam conducted by VIT University, Vellore | Ranked #16 by NIRF for Engg. | NAAC A++ Accredited
RV University, Bangalore | La...
Apply
Excellent curriculum; an impressive range of electives, besides core law courses. Up to 100% merit scholarship on a first-come, first-served basis
Amity University-Noida M.Tech...
Apply
Among top 100 Universities Globally in the Times Higher Education (THE) Interdisciplinary Science Rankings 2026
Amity University-Noida MBA Ad...
Apply
Ranked among top 10 B-Schools in India by multiple publications | Top Recruiters-Google, MicKinsey, Amazon, BCG & many more.
Great Lakes Institute of Mana...
Apply
Globally Recognized by AACSB (US) & AMBA (UK) | 17.8 LPA Avg. CTC for PGPM 2025
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