While running Usain Bolt covers certain distance at a speed of 30 km/hr and another distance which is thrice the earlier distance at 45 km/hr. Find the average speed of Usain Bolt. ?

40 km/h
45 km/h
30 km/h
35 km/h

LohaHridoy

4 views

2025-01-04 04:42

1 Answers

AhmedNazir

Option 1 : 40 km/h

Let the distance covered at 30 km/h be x km, then the distance covered at 45 km/h will be 3x km.
Total time taken to cover 3x km = (x/30) + (3x/45) = 9x/90 = x/10 hours
∴ Average speed = distance/time = 4x × 10/x = 40 km/h

4 views Answered 2022-09-04 04:29

Related Questions

A boat running downstream covers a distance of 20 km in 4 h. While coming back stream the boat takes 20 h to cover the same distance. Which of the following statements is/are correct 1. Speed of stream is 3 km/hr 2. Speed of boat is 2 km/hr?

1 Answers 4 Views

A pilot of steamer is going in downstream with certain speed. Suddenly he saw some people at the bank of river and turns steamer to 90° towards them. After 2 hours of journey he reached at bank of river but was at distance of 8 km from them. The shortest distance between the point of turning in the river to point of reaching at bank of river is 17 km. Find the downstream speed with which boat was moving earlier.?

1 Answers 7 Views

Consider the following statements about process state transitions for a system using preemptive scheduling. I. A running process can move to ready state. II. A ready process can move to running state. III. A blocked process can move to running state. IV. A blocked process can move to ready state. Which of the above statements are TRUE?

1 Answers 4 Views

Usain Bolt is associated with which sport?

1 Answers 4 Views

In the following question, a sentence / a part of sentence is underlined. Below are given alternatives to the underlined part which may improve the sentence. Choose the correct alternative. In case no improvement is required, choose "No Improvement" option. Usain Bolt is second to one as an athlete.?

1 Answers 4 Views

A train is running at a constant speed of X km/hour to cover a certain distance in time P hour. But, due to less visibility the driver reduces the speed of train by Y km/hour. If train takes T hours to cover the same distance, then which of the following is the correct relation between X, Y, P and T.?

1 Answers 4 Views

A man covers a certain distance(in m) in 15 minutes and then covers a distance which is equal to three times of the previous distance in 45 minutes and again travels a distance twice the previous distance in 1 hour 30 minutes. If the average speed of the man is 50 m/min, then find the half of the total distance covered by man.?

1 Answers 4 Views

Gaurav is facing North. He starts his bike and covers a distance of 15 km and then after keeping his bike in the parking he turns to his left and covers a distance of 8 km by walking to reach his home. There is another way from his starting point through which he can reach his home. Find the distance of this alternative way.?

1 Answers 4 Views

Prashant travelled from Lucknow to Aligarh which is 300 km away, by his car. He covered the distance, partly at an average speed of 45 km/h and partly at an average speed of 70 km/h. If he took 5 hours to complete his journey, then find the distance covered by him at the speed of 45 km/h.?

1 Answers 5 Views

A boatman wants to cross a river which distance is 80 km. In the starting boatman goes to 20 km and then turn 90 degree anti-clock wise and goes 60 km in upstream after that he turn 90 degree clock wise and goes 40 km. After that he turn 90 degree clock wise and goes 60 km. In the end he turn 90 degree anti-clock wise and goes 20 km and reach his destination. The speed of boatman is 22 km/hr and speed of stream is 4 km/hr. Find the time to cover total distance?

1 Answers 4 Views

এক্সাম দিয়ে মেধা যাচাই করুন

Job Preparation (1125)

Admission (754)

এসএসসি (10)

এইচএসসি (5)