Math Destroyer Test 11 #9

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Troyvdg

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I'm already bad at math and these explanations do not help haha,

In order for a console to operate, a green light and a red light must be lit simultaneously. If the red light randomly turns off 20% of the time and the green light randomly turns off 30% of the time, what percent of the time can the console be expected to not be working?

A: 44%

I understand that we solve this for the percentage of time that the light is on and then subtract from 100%

(100%-20%) x (100%-30%)= 56% of time that the light is on....but what I don't understand is how we can multiply these two percentages to solve this problem? weird thing not to understand, but maybe someone can help shed some light 🙄

thanks in advance!
 
When you use "and" you multiply. (When you use "or", you add.)
So probability of green light AND red light on is
P(G&R) = .8 (.7) = .56
subtract from 1 to get the probability of the console not working
Does that help any? o:
 
When you use "and" you multiply. (When you use "or", you add.)
So probability of green light AND red light on is
P(G&R) = .8 (.7) = .56
subtract from 1 to get the probability of the console not working
Does that help any? o:

so much swag. thank you!
 
[YOUTUBE]DwPDHVEHcvg[/YOUTUBE]

haha you reminded of this video. swag swag swoop~

After a long day studying, that seriously made my day. Swoop! by the way, I am still working on an answer to your question vlaura, I'll PM you tomorrow morning!
 
[YOUTUBE]DwPDHVEHcvg[/YOUTUBE]

haha you reminded of this video. swag swag swoop~

oh god...Gary I feel you're pain. the world's just not ready for us. It originated in berkeley and we're still suffering. #TYBG
 
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