Art of Problem Solving: Introducing Ratios

Art of Problem Solving's Richard Rusczyk introduces ratios.

[YAABKA]

the ratio of kids to adult at a party 5:2 ( It's really simple this is what you do ) Add together the ratio ( 5+2=7) Than the answer which is 7 multiply by the ratio example (7*5=35) and also ( 7*2=14) there are 35 kids and 14 adults

[evageorgieva]

If you are confused...

First Problem:
5+2=7
7x2=14 ( which is the number of adults)
we now know that we have to multiply 7 by 5 to find the number of kids:
7x5=35
and if you are asked to write your answer as a ratio:
35:14

*Always write the ratio the way they began it in the problem: KIDS TO ADULTS.

Second Problem:
5-3=2 ( to find the difference between adults and kids ) ( difference is 2 )
3x5=15 ( to find total number )
15-2=13
13x3= 39 (number of kids)
13x5=65 (number of adults)
and if you are asked to write your answer as a ratio:
39:65

*Always write the ratio the way they began it in the problem: KIDS TO ADULTS.

I hope that helped some of you. :)

[jaironeduque]

2021 still watching from 9 years before this video

[emmagracecooks]

are you kidding!! he is the best teacher EVER!! I have watched every other video about ratios and this one actually made sense! THANK YOU

[richaka]

Dude, you are making this harder than it is. 5kids = 2adults, xkids = 14Adults. solve for x? Cross multiply, you get 2x = 70, divide both sides by 2, you get x = 35.

[bnfopyk]

I was so lost in class but I knew I had u for backup 🎉🎉😂😅

[brisk]

Where did 13 come from in the 2nd problem

[escarface]

I've watched like 6 videos and this help put the final thought process into motion. I wish all videos would explain the thought process of the last problem. This is where most of the confusion comes from

[mashupervance]

Its so hard Uhmm.. 😤😥😧😩😰I have a question😑😮😴 | in 5:2= 2.5:2.2 | where did you get 2•5 and 2•2?😒😫😫😫

[khandohenders]

Thank you so much, ive struggled with this for long, but you have made it simple for me to understand.

[tarungogoi]

Thanks for making the video it helped me in the exam room

[ameenjakobra]

i didnt understand from this method :(

[saritasalome]

I don’t understand the 2nd problem 😩 how you get the 13 ?

[yolandasteenkamp]

ok so this is a easy way so the ratio of kids to adult at a party 5:2 ( It's really simple this is what you do ) Add together the ratio ( 5+2=7) Than the answer which is 7 multiply by the ratio example (7*5=35) and also ( 7*2=14) there are 35 kids and 14 adults

[raychellekrisbalolong]

I don't understand the second one

[kxcrimson]

you don't explained the problem!! you just worked it out like if we know!! very confusing!! please explain why u are doing each step!!! WHY!!!!

[dizzysdiamonds]

Wow ...that's how you start a video !!! Why didn't I have someone like you 25 years ago

[galaxycookie]

This is helpful as now we can not go to school because of corana, we can learn how to do Ratios from here, l was confused in Ratios but after watching this video l am not so thanks, l will share this video with my class.

[jasmeena]

Please could you write the English translation below (cc)

[markxsons]

Daniel's mother gives Daniel and his brother the same amount of allowance every month. By mistake, Daniel gets more allowance this month. The ratio of his allowance to his brother's allowance is 7 : 4. Daniel decides to give his brother some money so that both of them will have the same amount. If Daniel has $238 now, how much must Daniel give to his brother?

Plz reply...