Rajdhani express starts from Delhi at 7 : 00 AM with speed 105 km/hr and reaches Lucknow and stops there for 45 minutes. While returning from Lucknow it decreases its speed by 20% and reaches Delhi at 5 : 12 PM on the same day, then what is the distance between Delhi and Lucknow?
Rajdhani express starts from Delhi at 7 : 00 AM with speed 105 km/hr and reaches Lucknow and stops there for 45 minutes. While returning from Lucknow it decreases its speed by 20% and reaches Delhi at 5 : 12 PM on the same day, then what is the distance between Delhi and Lucknow? Correct Answer 441 km
Given:
Speed of Rajdhani express while going to Lucknow = 105 km/hr
Speed of Rajdhani while returning = 80% of 105 km/hr
Rajdhani Express stops at Lucknow station for 45 minutes
Formula Used:
Distance = Speed × Time
Calculation:
Let the distance between Delhi and Lucknow = D
Total time of the journey including stoppage time at Lucknow = 10 hours 12 minutes
Total time of the journey excluding stoppage time at Lucknow = 9 hours 27 minutes = 9.45 hours
Decreased speed = 80% of 105 = 84 km/h
According to the question :
⇒ (D/105) + (D/84) = 9.45
⇒ (4D + 5D)/420 = 9.45
⇒ 9D = 9.45 × 420
⇒ D = 441 km
∴ The distance between Delhi and Lucknow is 441 km.