# Problems on Trains Quiz Set 003

### Question 1

A train is running at a speed of 184km/h. If it takes 18sec to move past a telegraph pole, then what is its length?

A

920 meters.

B

921 meters.

C

919 meters.

D

922 meters.

Soln.
Ans: a

The total distance to be covered is equal to the length of the train. By the time and distance formula, we get length = time × speed × (5/18), which gives \$18 × 184 × (5/18)\$ = 920m. Please note that 5/18 is the conversion from km/h to m/s.

### Question 2

A train running at a speed of 19m/s crosses a pole in 18sec. How long will it take to cross a platform of length 684m?

A

54 sec.

B

55 sec.

C

53 sec.

D

56 sec.

Soln.
Ans: a

The length of the train can be obtained from the time it takes to cross the pole. The length of the train = \$19 × 18\$ = 342m. To cross the platform it must travel a total distance equal to the combined lengths of the train and the platform at this speed. So time = \${342 + 684}/19\$ = 54 seconds.

### Question 3

A train running at a speed of 18m/s crosses a pole in 16sec. How long will it take to cross a platform of length 864m?

A

64 sec.

B

65 sec.

C

63 sec.

D

66 sec.

Soln.
Ans: a

The length of the train can be obtained from the time it takes to cross the pole. The length of the train = \$18 × 16\$ = 288m. To cross the platform it must travel a total distance equal to the combined lengths of the train and the platform at this speed. So time = \${288 + 864}/18\$ = 64 seconds.

### Question 4

A train of length 119 m crosses a bridge at a speed of 45 km/h in 38 seconds. What is the length of the bridge?

A

6037 meters.

B

6038 meters.

C

6036 meters.

D

6039 meters.

Soln.
Ans: a

In 38 seconds the train covers a distance of 38 × 45 × (18/5) = 6156 meters. This distance is the sum of the lengths of the train and the bridge. Subtracting the length of the train we get the length of the bridge = 6156 - 119 = 6037 meters.

### Question 5

A train is running at a speed of 56m/s. If it takes 3sec to move past a telegraph pole, then what is its length?

A

168 meters.

B

169 meters.

C

167 meters.

D

170 meters.

Soln.
Ans: a

The total distance to be covered is equal to the length of the train. By the time and distance formula, we get length = time × speed, which gives \$3 × 56\$ = 168m.