A man covers a distance of 1200 km in 70 days resting 9 hours a day, if he rests 10 hours a day and walks with speed 1Â½ times of the previous in how many days will he cover 840 km ?
Options:
A) 25 days	B) 75 days	C) 35 days	D) 15 days	E) 05 days
Explanation:   Distance d = 1200km   let S be the speed   he walks 15 hours a day(i.e 24 - 9)   so totally he walks for 70 x 15 = 1050hrs.   S = 1200/1050 =&gt; 120/105 = 24/21 =&gt; 8/7kmph   given 1 1/2 of previous speed   so 3/2 * 8/7= 24/14 = 12/7   New speed = 12/7kmph   Now he rests 10 hrs a day that means he walks 14 hrs a day.   time = 840 x 7 /12 =&gt; 490 hrs   =&gt; 490/14= 
<gadget id="calculator">490/14</gadget>
<output>35</output>
35 days   So he will take 35 days to cover 840 km.   Answer: 35 days
<result>C</result>
A man covers a distance of 1200 km in 70 days resting 9 hours a day, if he rests 10 hours a day and walks with speed 1Â½ times of the previous in how many days will he cover 840 km ?