You know how to draw a tree diagram?
#maths question
sturdy orchid
dusk holly
ok
sturdy orchid
Do red and blue but don't put the probability
sturdy orchid
So all we know is that the combined probability of a blue being taken and another blue being taken is 1/20
dusk holly
ye
sturdy orchid
That means 1/4 × some probability = 1/20
sturdy orchid
Yes
So that's the probability that a blue counter is taken given that a blue counter has already been taken
dusk holly
ye
sturdy orchid
Can you send the probability tree you have so far?
sturdy orchid
Alr
sturdy orchid
Sorry I'm trying to think give me a minute
dusk holly
nw
sturdy orchid
Alright, so that means that because 1/5 is the probability of getting a second blue, the second red one would be 4/5 (because it's 1 - 1/5)
dusk holly
ok
sturdy orchid
Why can't I do this 😭 give me a minute again
dusk holly
ye no worries
it has this on the website
but i dont know what half of it is
i mean i guess
but i wouldnt be able to replicate it
sturdy orchid
Yeah that's 16 just did it
That's an interesting way though I didn't think of that
dusk holly
where is the 16 from
young maple
Well when it has these kind of questions I like to start by putting everything in the same variable, it becomes very easy from then on. If you use two, it still works but I don't like it personally
dusk holly
so ther is an easier way?
young maple
No
sturdy orchid
It's using x as the amount of blue counters at the start and 3x as the red counters at the start, then equating all of them to get x=4
dusk holly
ah
young maple
The model answer is very well done
sturdy orchid
Yes