Question on Permutation involving probability

[weak pasture]

Can you make it a little clearer

[ember chasm]

What to make clear

[weak pasture]

some words of the questions

what does 7/10 mean

[ember chasm]

ok

[weak pasture]

ok

[ember chasm]

is it fine now

[weak pasture]

I think here is wrong

[ember chasm]

Your answers are good

ik but why are you not supposed to arrange the biased dice as well

why you split it

whats the logic behind this

[weak pasture]

I know, you consider the order of the coins.

[ember chasm]

yeah

[weak pasture]

Every coin is the same, and the order in this case does not need to be considered

You flip four coins at the same time

[weak pasture]

here x =0 and x=4

doesn't consider the order

[ember chasm]

whats with the 3c1 in ur answer

calc for X=1

[weak pasture]

oh

\binom{3}{1}

choose one from three

the result is 3.

[ember chasm]

ik

choose one tail to be biased?

[weak pasture]

no

in situation B,
biased coin is tail.
we choose one fair coin to head and other 2 fair coins to tail

in situation A,
biased coid heads. and 3 fair coins tail

[ember chasm]

oh ok

[weak pasture]

P(A) +P( B) = P(x=1)

[weak pasture]

we don't need to choose which one is biased. we just consider that the biased coin heads or tails.

It only has these two cases

we always use the method of P(A) + P(B)

x=1 x=2 x=3

[ember chasm]

I understand your method

this another method I was shown

[weak pasture]

if you really need to consider the order.
I think x=0 should be 3/20 rather than 3/80.

[ember chasm]

You arrange the others and consider the Biased die as separate. But I dont get why it must be considered separate

[weak pasture]

but since it is 3/80. I think the question ignores the order.

[ember chasm]

its T subscipt nb***\

[weak pasture]

if there is no infomation of x=0 and x=4.

I think it is reasonable to consider the order, after all, the question is not clear, for example, four coins can be of different denominations

Penny Nickel Dime Quarter

[ember chasm]

💀

[weak pasture]

But isn't that overthinking things? In short, it is good to be able to justify, the process of thinking is important to get the numbers right.

[ember chasm]

You right my flaw is that I can be too perfectionist overthinking and shi

like to understand why things work the way it does

Thanks for the method you gave

[weak pasture]

More thinking is good, and more talking will make you better. The next time you have a similar problem, you won't have to struggle, because you already know both cases.

👍🏻

[ember chasm]

Bet. Have a great day bro

[weak pasture]

[ember chasm]

.solved