Question

The distance between two stations 'A' and 'B' is 300 km. A train starts from station
‘A’ with a speed of 30 km./hr. At the same time another train starts from station 'B'
in the opposite direction with a speed of 45 km./hr. At what distance from station
'A' will they meet?
(A) 100 km (B) 120 km. (C) 180 km. (D) 200 km​

Answer 1

ANSWER

Let the trains start from station A and station B respectively.

Let the first train start from station A and the second train start from station B at the same time and move towards each other.

Let the speed of the first train be x km/hr

∴ the speed of the second train =(x+20) km/hr

Distance travelled by first train in 2 hours =2x km

Distance travelled by second train in 2 hours =2(x+20) km =(2x+40) km

Given, distance between two stations =300 km

According to the given condition, we have

Distance travelled by first train + Distance travelled by second train +20=300

i.e., 2x+(2x+40)+20=300

4x+60=300

4x=300−60 ....[Transposing 60 to RHS]

4x=240

Thus, x=

4

240

=60

∴ Speed of the first train =60 km/hr and

speed of the second train =(60+20) krn/h =80 km/hr.

Answer 2

Answer:

B) 120 km

Step-by-step explanation:

Speed of the first train= 30km/hr

Speed of the second train=45km/hr

Time both trains will meet at = 300/30+45

=300/75= 4

So both trains will meet after 4 hours

Distance from station A = 4×30 = 120 km