Ravi jogs 7 km at a speed of 5 kmph. at what speed would she need to jog during the next 2.5 hour to have an average of 7 km per hr at the entire jogging session?  Select the correct option
A) 17.8 kmph
B) 8.9kmph
C) 5.8kmph
D) 5.8kmph
E) 4.9kmph
let speed of the jogging be xkmph   total time taken=(7/5+2.5)= 
<gadget id="calculator">(7/5+2.5)</gadget>
<output>3.9</output>
3.9hrs   total distance covered=(7+2.5x)   7+2.5x/3.9=9   x=17.8kmph   17.8 kmphnswer(17.8 kmph)
<result>A</result>
Ravi jogs 7 km at a speed of 5 kmph. at what speed would she need to jog during the next 2.5 hour to have an average of 7 km per hr at the entire jogging session?