answer
option d is the correct answer
explanation
as we know frequency is equal to 1 /t
f= 457 Hz
t=1
SO, 1/457
=0.0022sev
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Average speed is the ratio of total distance moved by Chi in total time interval
So here we will have
Total distance = 100 m + 400 m
Total time taken = 5 min + 15 min = 20 min
now by the formula of average speed we know that
so average speed will be 1.5 km/h
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