Rohit covers a certain distance by car. If he had increased his speed by 10 km/h, then he would have saved 2 hrs. But if he had decreased his speed by 20 km/h, then he would have taken 5 hrs more. What is the total distance covered?
Answer
Correct Answer : a ) 4200 km
Explanation :According to the question,
Let the normal speed be x km/h
If he had increased his speed by 10 km/h then he would have saved 2 hrs
We know that, If the same distance is travelled at two different speeds and the difference between the time taken in both cases is known then we can use the formula written below directly
D=\(S_1×S_2 \over S_1-S_2\)(Difference in time)
Where D, S1 and S2 are Distance, Normal speed, Increased or decreased speed
Substituting the values
⇒ \(D={{x (x+ 10)} \over { x+10-x}}*2\)
⇒\({{x (x+ 10)} \over 10}*2\)
⇒\({{x (x+ 10)} \over 15}\)…………1
If he had decreased his speed by 20 km/h, then he would have taken 5 hrs more
⇒D=\({{x (x - 20)} \over {x-x+20} } *5\)
⇒D=\({{x (x - 20)} \over {20} } *5\)…….2
Equating (1) and (2)
⇒\({{x (x + 10)} \over 5}={ {x(x-20)} \over 20 } *5\)
⇒ 4(x + 10) = 5(x – 20)
⇒ 4x + 40 = 5x – 100
⇒ x = 140 km/h
Substituting the value of x in eq (1)
D=\({{x (x +10)} \over 5} \)
⇒D=\({{140 *(140 + 10)} \over {5} }\)
⇒ D = 4200 km
Hence, (a) is the correct answer.
Share QOTD
Popular Blog
Highlights of Interim Budget 2024
Read More
150+ Paryayvachi Shabd in Hindi - पर्यायवाची शब्द
Read More
Highlights of G20 Summit 2023
Read More
SSC CHSL Tier 1 Exam Analysis 2023 - Questions Asked from 2 to 22 August 2023
Read MoreLatest Current Affairs
Daily Current Affairs and GK | 26 and 27 April 2024
Read More
Daily Current Affairs and GK | 25 April 2024
Read More
Daily Current Affairs and GK | 24 April 2024
Read More
Daily Current Affairs and GK | 23 April 2024
Read More
Daily Current Affairs and GK | 21 and 22 April 2024
Read More
Comments