Question

. A boy leaves his house at 9.30 a.m. for his school. The school is 2 km away and classes

start at 10.00 a.m. If he walks at a speed of 3 km/h for the first kilometre, at what speed

should he walk the second kilometre to reach just in time?

Answer 1

it means he had 30 minutes to reach the school
time taken to travel first km = (1/3)hours=20minutes
so the time left is =10minutes
=(1/6)hours
and distance which he still had to cover was 2km
so speed
=2÷(1/6)
=12 kmph.......................

Answer 2

Distance between school and home=2km
Total time=30 min=0.5 hours.
Initial speed =3km/hr for first 1km
Time taken for first 1 km =1/3hr
Time left =0.5-1/3=0.5/3 hr
Distance left=1km
Hence,
Speed of which he should walk the 2 km
=1/(0.5/3)=6km/hr.

Hope you like it...
Mark as brainliest...