Question

a boy ran a race of 400m at an average speed of 32km/hr. can you find the time taken by him to complete the race​

Answer 1

Answer:

To convert speed of m/sec into Km/ h, you have multiply by a factor of 18/5.

To convert speed of Km/ h into m/sec, you have to multiply by a factor of 5/18.

Here speed in m/sec is 400/45.

So speed in Km/ h

= 400/45 x 18/5

= 32- Km/ h

Answer 2

Answer:

I think this your answer

Step-by-step explanation:

Converting 400 m into km

We get 400/1000 = 2/5 km

Converting 20 s into hours

We get 20/ 60 × 60 or 20/3600 or 1/180 h

We know , Sppeed = Distance ÷ Time

Or 2/5 ÷ 1/180 or 2/5 × 180 or 72km/h is the required answer.