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 five 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).
Choose the correct choice from the following:
A) 65 minutes  B) 66 minutes  C) 56 minutes  D) 69 minutes  E) 46 minutes
Distance travelled by Ramu = 45 * 4= 
<gadget id="calculator">45 * 4</gadget>
<output>180</output>
180 km   Somu travelled the same distance in 5 hours.   His speed= 180/5= 
<gadget id="calculator">180/5</gadget>
<output>36</output>
36 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= 36 + 10= 
<gadget id="calculator">36 + 10</gadget>
<output>46</output>
46km/hr.   Therefore travel time of Ramu and Somu would be 5 hours and 3.9 hours respectively. Hence difference in the time taken= 1.1 hours = 66 minutes.   ANSWER:66 minutes
<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 five 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).