Rate problems in Pre-Algebra

Hello:

I am not sure what you mean. Did you not find the video helpful?  There are other tools within the subject that might be of help, such as the text and practice hints. 

The video was not helpful. There seems to be no logic to it. As I understand rate it's D=RT  Distance equals rate x time. The video is approaching way different than I can comprehend. I've looked at the hints and it leaves a lot. So every one of the three questions I have blown on the Mastery. I'm looking at other websites, no help there either. So figure I will buy an algebra text somewhere to see if there is another approach to the distance/Rate/time questions. Sorry if I've been a bother.

Hi Patricia-

There are many different types of rates.  You are correct that ONE formula that involves SPEED ( atype of rate)  is d=rt (distance equals rate (speed) times time.  However, 20 cats per day is also a rate because the units on top (cats) is different from the units on bottom (days.)  Many of the problems on the rate exercises on Khan are most easily solved by writing equivalent rates or by solving proportions.  For example: 20 cats per day is the same rate as 40 cats per 2 days.  It is also the same as 10 cats per 1/2 day.  If you wanted to know how many cats you would have in 3.5 days you could solve the proportion 20 cats over 1 day = x cats over 3.5 days.  I am not sure if this helps- I am not sure which problem you are struggling with specifically- but I do hope you keep at it!