Question

a car travels at a speed of 40 km per hour for 5 minutes and then 50 km per hour for 10 minutes and finally at 25 km per hour for 15 minutes find average speed

Answer 1

here u go ;)..........

Answer 2

first convert minute into hours
5 min= 5/12hours
10min= 10/12 hr
15 min= 15/12=
avg speed= avg distance/total time
avg speed,
$= 40 \times (5 \div 12) + 50 \times (10 \div 12) + 25 \times (15 \div 12) \: whole \: divide \: by \: 5 \div 12 + 10 \div 12 + 15 \div 12$
now you can calculate it...
hope it helped you