Question

@ amistre64 , using the method that you taught me, how would I solve:
A cyclist travels 20km in 4hrs. What speed did the cyclist cycle at?

Answer 1

You need to view this as a units problem. You want a solution in units of \[\frac{km}{hr}\]
You have 20km and 4hrs. What do you think you need to do to get the units we seek?

Answer 2

\[speed = \frac{20}{4}\]
\[speed = 5km/hr\]

Answer 3

Keep in mind the value sticks with the unit:
\[\frac{20km}{4hr}\]

Answer 4

sorry everybody keeps confusing me with their different methods

Answer 5

At the end of the day you stick with the method that works for you. The answer should be the same regardless of method.

Answer 6

As Saifoo stated above you shoudl get a result of \[5\frac{km}{hr}\]

Answer 7

http://openstudy.com/groups/mathematics#/groups/mathematics/updates/4e5e651e0b8b1f45b498e7d6, this is the method I would like to use if possible

Answer 8

the method I was using is similar to cross multiplication

Answer 9

I looked at http://openstudy.com/groups/mathematics#/groups/mathematics/updates/4e5e651e0b8b1f45b498e7d6
The reason why amistre64 used crossmultiplication was to convert mintues into hours. In this problem you already have the hours. No need to convert.

Answer 10

bloody hell

Answer 11

so I cant use it universally

Answer 12

You can use what Amistre showed you. He was cancelling units. i.e. converting minutes to hours:
\[30 minutes\frac{1 hours}{60 minutes}=\frac{1}{2} hours\]
We just didn't need to cancel units.