A person completes half distance of marathon in 20 min including 7 minutes of break time.He runs at 5m/s. Then what is total distance covered if he runs at constant speed and takes only one break in entire marathon. Select.
A) 8km  B) 7.8km  C) 9km  D) 6.1km  E) 7km
Considering and removing break he runs only for 13 min ie 780 s.So total time =780*2= 
<gadget id="calculator">780*2</gadget>
<output>1_560</output>
1560.   Total distance=1560*5= 
<gadget id="calculator">1560*5</gadget>
<output>7_800</output>
7800m   Thus 7.8km   Answer:7.8km
<result>B</result>
A person completes half distance of marathon in 20 min including 7 minutes of break time.He runs at 5m/s. Then what is total distance covered if he runs at constant speed and takes only one break in entire marathon.