Question : Aman decided to cover a distance of 12 km in 78 minutes. He decided to cover the initial two-thirds of the distance at 10 km/hr and the remaining at some different speed. Find the speed for the last one-third of the distance.
Option 1: 7.8 km/hr
Option 2: 8 km/hr
Option 3: 8.4 km/hr
Option 4: 9 km/hr
New: SSC CHSL tier 1 answer key 2024 out | SSC CHSL 2024 Notification PDF
Recommended: How to crack SSC CHSL | SSC CHSL exam guide
Don't Miss: Month-wise Current Affairs | Upcoming government exams
Correct Answer: 8 km/hr
Solution :
Time taken to cover a distance of 12 km = 78 minutes
Two-thirds of the 12 km was covered at = 10 km/hr
Time = $\frac{\text{Distance}}{\text{Speed}}$
Two thirds of $12$ km = $12\times{\frac{2}{3}}$ = 8 km
Speed for 8 km distance cover = 10 km/hr
So, Time = $\frac{8 }{10}$ = 0.8 h = 48 minutes
⇒ Time left = 78 – 48 = 30 minutes = $\frac{30}{60}$ = 0.5 hour
Remaining distance = 12 – 8 = 4 km
⇒ Speed required for remaining 4 km = $\frac{4\mathrm{~km} }{0.5 \mathrm{~h}}$ = 8 km/hr
So, the speed for the last one-third of the distance is 8 km/hr.
Hence, the correct answer is 8 km/hr.
Related Questions
Know More about
Staff Selection Commission Combined High ...
Result | Eligibility | Application | Admit Card | Answer Key | Preparation Tips | Cutoff
Get Updates Brochure
Your Staff Selection Commission Combined Higher Secondary Level Exam brochure has been successfully mailed to your registered email id “”.
