If you're seeing this message, it means we're having trouble loading external resources on our website.

Хэрэв та вэб шүүлтүүртэй газар байгаа бол домэйн нэрийг *.kastatic.org and *.kasandbox.org блоклосон эсэхийг нягтална уу.

Үндсэн товъёог
Цаг: 0:00Нийт үргэлжлэх хугацаа:6:02

Video transcript

what we're going to do in this video is tackle some word problems involving ratios so here we're told that Yoda soda is the intergalactic party drink that will have all of your friends saying mmm good this is you are throwing a party and you need 5 liters of Yoda soda for every 12 guests if you have 36 guests how many liters of Yoda soda do you need so pause this video and try to figure it out on your own well they tell us the ratio of liters of soda to number of guests so you need 5 it's a 5 liters for every 12 guests is the ratio but we want to have 36 guests so if the ratio is 5 liters of soda for every 12 guests but we're in a situation where we have 36 guests so this is 3 times as many guests we're going to need three times as many liters of soda so 3 times 5 is 15 5 to 12 5 liters for 12 guests or for 5 liters for every 12 guests is the same thing as 15 liters for every 36 guests so to answer that question how many liters do you need you need 15 liters let's do another one of these here we just have a picture of a bunch of fish in a tank and it says there are eight big fish for every blank small fish and then it says there are four big fish for every blank small fish so pause this video again and see if you can work through this all right so let's just count the big fish first so there's one two three and then we count this way one two three four five six seven eight so in this tank there actually are eight big fish and so let's see how many small fish there are there's 1 2 3 4 5 6 7 8 9 10 small fish so in the tank for every 8 big fish which you see in red there are 10 small fish but here it says there are 4 big fish for every blank small fish so what would that be well one way to think about it we have half as many fish we are half as many big fish so we divided it by two so we're gonna have half as many small fish so we're gonna divide by two so for every four big fish there are five small fish and one way to think about it you could divide the fish evenly into two groups right over here so let's see if we can capture so if you could have this is if I divide it like that here I have 1 2 3 4 big fish and 1 2 3 4 5 small fish then in this group I have 1 2 3 4 big fish and 1 2 3 4 5 small fish so every four big fish there are 5 small fish these are equivalent ratios let's keep going so here we're told an ice-cream shop uses the following ingredients to make one Sunday so they use 2 scoops of ice cream four spoonfuls of sprinkles 2 tablespoons of whipped cream how many sundaes did the shop make if they used 32 spoonfuls of sprinkles so pause the video and try to think about it so there's a couple of ways to think about it here it says I see we're talking about sprinkles so that's what's relevant here four spoonfuls for every one Sunday so we could say that there so the ratio of spoonfuls to sundaes is four to one four spoonfuls spoon fulls of sprinkles let me write it this way let me write it sprinkles sprinkles how many spoonfuls how many spoon fulls per one Sunday but here we're talking about using 32 spoonfuls of sprinkles so that is eight times as many so you're going to be able to use create eight times as many sundaes so you're gonna have 32 spoonfuls of sprinkles for every eight Sundays so how many Sundays did the shot make well they made eight let's do one last example at a dog park there are 10 black dogs 5 brown dogs 2 white dogs and 12 multicolored dogs for every one brown dog there are two blank dogs pause the video and figure out what goes in this blank alright so let's see there's five Brown dogs for every ten black dogs five Brown dogs for every two white dogs and five Brown dogs for every 12 multicolored dogs but here you're saying for every one brown dog there are two blank dogs so what type of dog is their ratio so for every brown dog there's twice as many of that type of dog well here we see for every five Brown dogs there are ten black dogs so one way to think about it the number of black dogs is always going to be twice the number of brown dogs so for every one brown dog there would be two two black to black dogs one way to think about it the ratio between brown dogs and black dogs and it's kind of counterintuitive I use the wrong color see I should use brown and black so let me do that so the ratio of brown to black is five Brown dogs for every 10 10 black dogs or if you divide both of these numbers by five you would get one one brown dog for every two for every two black dogs and that's exactly what this statement is saying