Question

Janet ran 3.8 km in 40 minutes.Work out her average speed in km/h.

Answer is not important, rather the workings

Answer 1

3.8*1/(2/3) = 3.8*3/2 = 1.9*3 =5.7

Janet ran at 5.7 km/h

Answer 2

2/3=40/60?

Answer 3

\[speed=distance/time\]
40 minutes=40/60=2/3 hours

Answer 4

yep

Answer 5

@ mathematical pro

Answer 6

the last question you helped me with was also finding the average speed, why is this question solved differently to the previous

Answer 7

nope it was distance

Answer 8

oh sorry

Answer 9

Oh yes i mistaked ><

Answer 10

http://openstudy.com/groups/mathematics#/groups/mathematics/updates/4e5e21ab0b8b1f45b4980983 this is also a finding average speed question which is solved different ly to this one

Answer 11

is there a universal formula for finding average speed that always works regardless of the different units?

Answer 12

distance / time to do this distance

Answer 13

marleythemongoose :
Average speed = (total distance covered( / (total time taken)???

Answer 14

Here the correct answer his 3.8/(2/3) = 3.8*3/2 = 1.9*3 = 5.7 this is the same response that last time, but last time I calculed the distance Janet could have run in an hour with the same speed she ran to do the 3.8 km

Answer 15

is it a different formula for different units of time??

Answer 16

yup

Answer 17

ok so for seconds you just divide distance by time

Answer 18

and for minutes you do (minutes/ 1 hour) and the * the distance?

Answer 19

............?

Answer 20

Average speed = (total distance covered) / (total time taken)

and you have the average spped in the unit : unit of the distance / unit of the time
you just have to convert to havee the unit you wanbt

Answer 21

sorry i just forgot to cilc post ....