Which expression calculates the speed in meters per second of an object that travels a distance of 100 m every 20 s?

Step-by-step explanation:

Alright, lets gets started.

We have given the distance as 100 meters.

The time for completing this distance is 20 seconds.

The formula for calculating speed is :

Hence plugging the values of distance and time in formula,

meters per second

We could further simplify this speed to 5 meters per second, but as the expression is asked in question, we will given answer meters per second.  

Hope it will help :)

option a is correct.

step-by-step explanation:

scale factor: it is used to find proportional measurements.

proportions means having the same ratio.

scale factor is the ratio of the model measurement to the actual measurement in a simplest form.

or we can say that the ratio of any two corresponding lengths in two similar geometric figures

if the scale factor is more than 1, then it is an enlargement,

if the scale factor less than 1, then it is a reduction.

given the two geometric figure:

by definition of proportions, we have