Ramu rides his bike at an average speed of 45 km/hr and reaches his desitination in four hours. Somu covers the same distance in six hours. If Ramu covered his journey at an average speed which was 9 km/hr less and Somu covered his journey at an average speed which was 10 km/hr more, then the difference in their times taken to reach the destination would be (in minutes).
Answers:  A) 22 min  B) 30 min  C) 87 min  D) 26 min  E) 11 min
Explanation:   Distance travelled by Ramu = 45 x 4 = 180 km   Somu travelled the same distance in 6 hours.   His speed = 180/6= 
<gadget id="calculator">180/6</gadget>
<output>30</output>
30 km/hr   Hence in the conditional case, Ramu's speed= 45 - 9= 
<gadget id="calculator">45 - 9</gadget>
<output>36</output>
36 km/hr and Somu's speed= 30 + 10= 
<gadget id="calculator">30 + 10</gadget>
<output>40</output>
40km/hr.   Therefore travel time of Ramu and Somu would be 5 hours and 4.5 hours respectively.   Hence difference in the time taken= 0.5 hours = 30 minutes.   Answer: 30 min
<result>B</result>
Ramu rides his bike at an average speed of 45 km/hr and reaches his desitination in four hours. Somu covers the same distance in six hours. If Ramu covered his journey at an average speed which was 9 km/hr less and Somu covered his journey at an average speed which was 10 km/hr more, then the difference in their times taken to reach the destination would be (in minutes).