Hello, this is the second lesson on ratios or ratios part 2 for the pre algebra level of math
We're going to be talking about ratios today a little bit about how to use them more practically
The first thing I'd like to point out is that you can see the ratios before whether you recognize it or not ratios for example here's one
Speed is a ratio often called great or velocity, but we're gonna call speed for now it's a ratio of, for example miles per hour the distance you travel in a certain amount of time we write just like that miles per hour or you can write it as a fraction miles over at the hour's or you can't just say miles per hour anyway that's a ratio
The next ratio: talk about is if you have a vehicle and you look down you see rpm that is rotations per minute so that is another ratio it's a ratio how many times it rotated in each minute
The third ratio I'd like to talk about come I don't know I was just thinking about different things that might not have parts-per-million with you, eat food like I was visiting a Hershey factory and one other students there ask the question how many parts per million Are bug pieces so they have a certain amount you know they're quality testing it has to be below a certain amount so they do measure it in parts per million so it really is not a lot about your eating not getting a great deal protein with that but I just one see in Tv put these ratios in everyday life that would be a ratio Bug parts or foreign object for the amount of food parks current like that little warm inside the Apple.
We're gonna look at how to actually solve ratios the first ratio out here saying i eat 15 eggs in five minutes what is the Ratio of eggs per minute?
The first thing I'm going to do is write this as fraction I just sometimes I read it as a fraction sometimes alright, it with the column between sometimes alright it in words you could Solve ratios either way, whichever way you want artists chosen to use fractions this time so I write it with eggs and minute and substituted the amount to have, I know that I have 15 eggs And 5 minutes so I can substitute that value right into the fraction now I have a fraction I know I eat 15 eggs per 5 minutes I want to reduce that to find out how many eggs I eat in one minute so I'm going to divide each term by 5 so 15 divided by 5 is 3, 5 divided by 5 is one so in other words I will eat 3 eggs per minute I can write that in a sentence, there is how I would set up just type of Question.
Let's look at some more examples write the ratio in lowest terms of me driving
100 miles in 4 hours the first thing I'm going to do is of setup my ratio miles to hours
How many miles for each hour you can use your ratios which ever way you feel comfortable I have 100 miles in 4 hours I m tryin reduce that down to lowest terms and I'll do that by dividing 100 and 4 by the greatest common factor in this case is 4, i divide each term by 4 and will give the final ratio up 25 To 21 in other words I Drive 25 miles per power alright. I reduce unique ratio down to the lowest terms and now I'm driving 25 miles in one our 25 per 1, 25 miles per hour
If I can fit 12 people in 3 cars how many people are there per car? So I'm setting up a ratio of people to cars this is how I'm going to solve it using the written way people in cars are 12 to 3 Is 12 people in 3 cars I'm trying to find how many people per car so again I'm going to be reduced down to its lowest terms and to do that I will divide each By 3 the greatest common factor and this gives me the final answer that I'm going to fit 12 divided by 3 is 4 to 1. 4 people to 1 car so I can write that my final answer I Said 4 people per car on average right maybe there's five people in one card only three in another something but it is 12 people in three cars there's an Average 4 people per car this is just pretty simple straightforward 4 people 1 car
Would look at another ratio question if there are 32 slices of pizza in 4 pizzas write the ratio of slices per pizza. Slices, Pizza I’ll do this within a fraction I really do like how the fractions work just because reducing fractions to its lowest terms is something that all of us have done so it's something that's a little bit more familiar so I will go write up my fraction
Are Slices and Pizzas have 32 slices per 4 pizzas I find my common factor between the two is 4 so I divide each by 4 and I have 32 divided by 4 is 8 and 4 divided by 4 is 1 and now we have 8 over 1 so we know that we have 8 pizza slices for each Pizza makes sense, so write that down we have 8 slices per pizza now we have 4 pizzas with 8 slices Per pizza 4 times 8 is 32 slices of pizza it's all OK
The last question that we're gonna be working in is Jim types 480 words in 8 minutes how many words per minute does Jim type?
I will use the colon i put it in words to minutes(words : minutes) how many words does, he types? 480 words in 8 minutes is a ratio of 480 to 8 and we're going to reduce that down the lowest terms by dividing each term by 8, and a quick way to do 480 divided by 8 Is just to look at and say, well what's 48 divided by 8 just a quick trick 48 divided by 8 is 6 and we ad next to the 6 a zero. And we get 60 and 8 to 8 is 1 We get 60 to 1 so Jim types 60 words per minute wpm 
So that some the common ways that we are seeing ratios in our everyday lives and this is actually we're doing a lot of the same things that we've done before reducing Fractions to lowest terms looking for greatest common denominators.
Have all a wonderful day