23 Views

Question : Having started from the same point simultaneously, two runners P and Q are running around a circular track of length 500 m in opposite directions with speeds of 6 m/s and 10 m/s, respectively. If they exchange their speeds after meeting for the first time, who will reach the starting point first?

Option 1: Q

Option 2: P

Option 3: Both P and Q will reach at the same time

Option 4: No one of the P and Q


Team Careers360 11th Jan, 2024
Answer (1)
Team Careers360 20th Jan, 2024

Correct Answer: Both P and Q will reach at the same time


Solution : Two runners P and Q run in a circular track of length with speeds 6 m/s and 10 m/s.
The time they meet for the first time $=\frac{\text{Length of Circular Track}}{\text{Relative Speed}}$
$= \frac{500}{10 + 6} = \frac{500}{16} = \frac{125}{4}$ sec
Now, Distance covered by P $= 6\times \frac{125}{4}=\frac{375}{2}$ m
And distance covered by Q $=10\times \frac{125}{4}=\frac{625}{2}$ m
After interchanging their speeds,
Speed of P = 10 m/s
Speed of Q = 6 m/s
The remaining distance for P and Q will be equal to (500 – Distance covered respectively)
Time taken by P to reach the starting point $= (500-\frac{375}{2})\times\frac{1}{10}$
$= \frac{625}{20}=\frac{125}{4}$ sec
Time taken by Q to reach the starting point $=(500-\frac{625}{2})\times\frac{1}{6}$
$= \frac{375}{12} = \frac{125}{4}$ sec
$\therefore$ They will reach the starting point at the same time.
Hence, the correct answer is both P and Q will reach at the same time.

SSC CGL Complete Guide

Candidates can download this ebook to know all about SSC CGL.

Download EBook

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
GRE ® Registrations 2024
Apply
Apply for GRE® Test now & save 10% with ApplyShop Gift Card | World's most used Admission Test for Graduate & Professional Schools
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