Aryan runs at a speed of 40 metre/minute. Rahul follows him after an interval of 5 minutes and runs at a speed of 50 metre/minute. Rahul's dog runs at a speed of 60 metre/minute and start along with Rahul. The dog reaches Aryan and then comes back to Rahul, and continues to do so till Rahul reaches Aryan. What is the total distance covered by the dog? Choose one:
A) 1100 meters
B) 1200 meters
C) 1250 meters
D) 1300 meters
E) 1400 meters
Let X = Minutes   And Y = Aryan runs speed = 40 meter per X   And Z = Rahul runs speed = 50 meter per X (i.e., 200 + 50x)   And D = Total distance covered by the dog = X* 60meters   Y = Z   40x = 200 + 50x   200 = 10x   x = 200/10= 
<gadget id="calculator">200/10</gadget>
<output>20</output>
20   So, by 20minutes, both Aryan and Rahul meets.(Rahul reaches Aryan.)   So, dog covered distance, D= X * 60 meters = 20*60= 
<gadget id="calculator">20*60</gadget>
<output>1_200</output>
1200 meters   ANSWER:1200 meters
<result>B</result>
Aryan runs at a speed of 40 metre/minute. Rahul follows him after an interval of 5 minutes and runs at a speed of 50 metre/minute. Rahul's dog runs at a speed of 60 metre/minute and start along with Rahul. The dog reaches Aryan and then comes back to Rahul, and continues to do so till Rahul reaches Aryan. What is the total distance covered by the dog?