Question
Download Solution PDFA policeman chases a thief on a straight road. The policeman catches the thief in 15 minutes if he drives with a speed of 60 km/h and catches the thief in 0.5 hours if he drives with a speed 45 km/h. What should be his driving speed (in km/h) to catch the thief in just 10 minutes?
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFGiven:
Speed of policeman = 60 km/h, time = 15 minutes (0.25 hours)
Speed of policeman = 45 km/h, time = 0.5 hours
Time to catch the thief = 10 minutes (1/6 hours)
Let Speed of thief = x km/hr.
Speed of policemen as v km/hr when to catch in 10 minutes.
Formula used:
Relative Speed = Speed of Policeman - Speed of Thief
Distance = Relative Speed × Time
Calculation:
Relative speed = 60 - x and 45 -x in two cases respectively.
Set the distances equal for both cases:
0.25(60 - x) = 0.5(45 - x)
⇒ x = 30 km/h (thief's speed)
To catch the thief in 10 minutes:
7.5 = (v - 30) × 1/6
⇒ v = 75 km/h
∴ The required speed is 75 km/h.
Last updated on Jun 3, 2025
-> The Staff Selection Commission has officially released the SSC Selection Post Phase 13 Notification 2025 on its official website at ssc.gov.in.
-> A total number of 2423 Vacancies have been announced for various selection posts under Government of India.
-> The Computer Based Exam is scheduled from 24th July to 4th August, 2025. Candidates will be able to apply online from 2nd June 2025 to 23rd June 2025.
-> The SSC Selection Post Phase 13 exam is conducted for recruitment to posts of Matriculation, Higher Secondary, and Graduate Levels.
-> The selection process includes a CBT and Document Verification.
-> Some of the posts offered through this exam include Laboratory Assistant, Deputy Ranger, Upper Division Clerk (UDC), and more.
-> Enhance your exam preparation with the SSC Selection Post Previous Year Papers & SSC Selection Post Mock Tests for practice & revision.