how can we solve this question

A-----------B-----------C
let A is anand house
B is1km distance apart from his house
C is school
we know time =distance/speed
tAB=1/3 hour
tAB is time taken from A to B
tBC=1/2-1/3 =1/6hour
so, speed = distance/time = 1/(1/6) = 6km/h

Hope It Helps :)
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