A train covered half of the distance between stations A and B at the speed of 48 km/hr, but then it had to stop for 15 min. To make up for the delay, it increased its speed by 53 m/sec and it arrived to station B on time. Find the distance between the two stations and the speed of the train after the stop.
Answers:
A) 206 B) 216 C) 226 D) 256 E) 246
First let us determine the speed of the train after the stop. The speed was increased by 53 m/sec =5⋅60⋅6031000 km/hr = 6 km/hr. Therefore, the new speed is 48+6= 
<gadget id="calculator">48+6</gadget>
<output>54</output>
54 km/hr. If it took x hours to cover the first half of the distance, then it took x−1560=x−0.25 hr to cover the second part.   So the equation is: 48⋅x=54⋅(x−0.25)   48⋅x=54⋅x−54⋅0.25   48⋅x−54⋅x=−13.5   −6x=−13.5   x=2.25 h.   The whole distance is   2×48×2.25=216 km.   Answer is 216.
<result>B</result>
A train covered half of the distance between stations A and B at the speed of 48 km/hr, but then it had to stop for 15 min. To make up for the delay, it increased its speed by 53 m/sec and it arrived to station B on time. Find the distance between the two stations and the speed of the train after the stop.