Question - Find average Speed of Runner?

A) 12.8 km/h
B) 6 km/h
C) 8.8 km/h
D) 10.2 km/h
E) 6.6 km/h?

Question

Question - Find average Speed of Runner?

A) 12.8 km/h
B) 6 km/h
C) 8.8 km/h
D) 10.2 km/h
E) 6.6 km/h?

Aanchal Tyagi · Accepted Answer

To find the average speed for the entire race, we need to use the formula: 
average speed = total distance / total time 
We know the total distance is 10 km, but we need to find the total time. To do that, we can use the formula: 
time = distance / speed 
We can find the time taken for each segment of the race by using the given information. The time taken for the first 4 km is: 
time = 4 / 12 time = 0.333 hours 
The time taken for the next 2 km is: 
time = 2 / (12 * 1.5) time = 2 / 18 time = 0.111 hours 
The time taken for the last 4 km is: 
time = 4 / 12 time = 0.333 hours 
Therefore, the total time is: 
total time = 0.333 + 0.111 + 0.333 total time = 0.777 hours 
Now we can plug in these values into the average speed formula and simplify: 
average speed = 10 / 0.777 average speed = 12.871 km/h 
Therefore, the average speed for the entire race is 12.871 km/h
Correct Option is A.

Question - Find average Speed of Runner? A) 12.8 km/h B) 6 km/h C) 8.8 km/h D) 10.2 km/h E) 6.6 km/h?