Dr. Lal and Jain Solutions for Chapter: Speed, Time and Distance, Exercise 1: Exercise

A train running with a uniform speed crosses a platform in $20$ seconds. To determine the speed of the train, the knowledge of which of the statements (a) and (b) is/are sufficient?
(a) Length of the train
(b) Length of the platform

A train is running at the speed of $84 \mathrm{km}/\mathrm{hr}$. If it passes a man walking in opposite direction at the speed of $6 \mathrm{km}/\mathrm{hr}$ in$4$ seconds, what is the length of the train in metre?

If a $100$ metre long train which is moving at $50 \mathrm{km}/\mathrm{hr}$, crosses another train which is $120$ metre long and moving in the opposite direction in $6$ seconds. What is the speed of the second train?

A train running at a speed of $120 \mathrm{km}/\mathrm{hr}$ crosses another train running in the opposite direction in $9$ seconds.

To find out the length of the first train, the knowledge of which of the statements (P) and (Q) is/are sufficient?

(P) Speed of the second train

(Q) Length of the second train

A boat travels from P to Q along the current and from Q to P against the current in $3$ hours. If the speed of the boat in still water is$4 \mathrm{km}/\mathrm{hr}$ then, what is the distance between P and Q?

A train running at $90 \mathrm{km}/\mathrm{hr}$ crosses a pole in $10$ seconds. What is the length of the train?

Train A crosses another train B running in opposite direction in $9$ seconds. What is the speed of the train A?

To know the answer of this question, the knowledge of which of the following statement is/are sufficient?

(a) Speed of the train B

(b) Length of the train A

(c) Length of the train B

$150$ metre long train takes $10$ seconds to pass a man who is going in the same direction at the speed of $2 \mathrm{km}/\mathrm{hr}$. What is the speed of the train?