Mary jogs 9 km at a speed of 6kmph. at what speed would she need to jog during the next 1.5 hour to have an average of 9 km per hr at the entire jogging session? Choose the correct choice from the following choices
A) 12kmph	B) 7kmph	C) 87kmph	D) 74kmph	E) 78kmph
let speed of the jogging be x kmph   total time taken=(9/6+1.5)= 
<gadget id="calculator">(9/6+1.5)</gadget>
<output>3</output>
3 hrs   total distance covered=(9+1.5x)   9+1.5 x/3=9   9+1.5 x=27   3/2x=18   x=18*2/3= 
<gadget id="calculator">18*2/3</gadget>
<output>12</output>
12 kmph   12kmphnswer(12kmph)
<result>A</result>
Mary jogs 9 km at a speed of 6kmph. at what speed would she need to jog during the next 1.5 hour to have an average of 9 km per hr at the entire jogging session?