Geometric distribution

[light niche]

I’m guessing this is geometric but how do I solve this, I keep getting x to be negative

[topaz field]

I think its binomial

find the probability of at least one success in n trials

X~B(n,0.1)
P(X>=1) = 1-P(X=0)
= 1 - (1-p)^n
1 - 0.9^n < 0.5

[light niche]

How did u tell it was binomial

[vapid pewter]

It's kinda implied that the game is over when they roll the 10 though (since they've won already)
but you should be looking at P(X<=x) I think and not P(X=x)

so geometric does work here

[light niche]

Oh okay I see

How were u able to tell irs <=

[vapid pewter]

since it says they roll the dice multiple times (not the exact number) they could win on the 1st, 2nd, 3rd, ..., nth role right

[light niche]

Ohhhh

[vapid pewter]

and you want the sum of that probability to be less than 0.5

[light niche]

I see

Thank you

[vapid pewter]

np