Two men starting from the same place walk at the rate of 5 kmph and 5.5 kmph respectively. What time will they take to be 7.5 km apart, if they walk in the same direction? Choices
A) 12 hrs B) 14 hrs C) 15 hrs D) 17 hrs E) None
Sol.   to be 0.5 km apart, they take 1 hour.   To be 7.5 km apart, they take [1/0.5 * 7.5= 
<gadget id="calculator">1/0.5 * 7.5</gadget>
<output>15</output>
15 hrs.   Answer 15 hrs
<result>C</result>
Two men starting from the same place walk at the rate of 5 kmph and 5.5 kmph respectively. What time will they take to be 7.5 km apart, if they walk in the same direction?