Question

A line is graphed to show the relationship between the number of words typed and the time Mary spends on a typing test.

Answer 1

The answer to your question is : The value of y increases by 40 for each increase of 1 by x .

Things you could of looked out for:
A. is wrong because 40 isn't plotted on the x-value
C and D are wrong because there isn't 140 plotted on either.

Hope this helps you!

Answer 2

Thanks for including the graph! 

Okay, so -

From examining the graph, we can see that for every minute the number of words increases by 40. 

Now, since the x axis (the horizontal thingy kabob at the bottom) is time, and the y axis (the vertical thingy kabob) is the number of words - we can conclude that the answer is B! 

Just remember that the value of the y axis is dependent on the value of the x axis. Also, note that x almost always represents time!