Question

An aeroplane takes 3600 seconds to travel 500 km. If it increases its speed for 12.5 km per minute, how many minutes less will it take to travel the same distance ? ​

Answer 1

Aeroplane covers 500 km in 3600 sec i.e. in 60 min.

so speed= dist./ time

= 500/ 60 = 50/6 km/min

increase in speed is 12.5 km/min

hence total speed is ( 50/6 +12.5) km/min

it covers the same distance of 500 km with new speed

time taken= dist./ speed

= 500/ (50/6 + 12.5)

= 500 / (50+75 /6)

= 500 / (125/6)

= 500×6/125

= 4× 6 = 24 min

time during first flight is 60 min and during 2nd flight is 24 min.

hence decrease in time= 60 - 24= 36 min

36 min less it will take to cover the same distance.

Answer 2

Answer:

ans is 36

Step-by-step explanation:

36 less

option

B