Question : Speed of stream is 4 km/hr and the speed of boat is 11 km/hr. In how much time will the boat cover a distance of 21 km upstream and 45 km downstream?
Option 1: 6 hours
Option 2: 3 hours
Option 3: 4 hours
Option 4: 7 hours
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: 6 hours
Solution :
The speed of the stream is 4 km/hr.
The speed of the boat is 11 km/hr.
Upstream Speed = Speed of boat –Speed of stream
= 11 – 4 = 7 km/h
Upstream distance = 21 km
Time = $\frac{21}{7}$ = 3 hrs
Downstream Speed = Speed of boat + Speed of stream
= 11 + 4 = 15 km/h
Downstream distance = 45 km
Time = $\frac{45}{15}$ = 3 hrs
Total time = 3 + 3 = 6 hrs
Hence, the correct answer is 6 hours.
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 “”.
