# URGENT! Need help with probability question (1 Viewer)

#### Danneo

##### Member
Thank god if someone replies as HSC math is within a few hours

-If 3% of coins produced are faulty, what is the probability that a sample of 3 coins taken from the production line will have atleast two faulty coins

I keep getting the quesiton wrong

Ans = 1323/500000 (I think thats the right ans)

#### InteGrand

##### Well-Known Member
Thank god if someone replies as HSC math is within a few hours

-If 3% of coins produced are faulty, what is the probability that a sample of 3 coins taken from the production line will have atleast two faulty coins

I keep getting the quesiton wrong

Ans = 1323/500000 (I think thats the right ans)

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Last edited:

#### HeroWise

##### Active Member
Imagine this comes in the HSC

• InteGrand

#### Danneo

##### Member
Holy crap, this just changed how i see binomial, so just tested 1 - (P(No faults) + (1 fault))
P(No faults) = (97/100)^3
P(Exactly 1 fault) = 3C1*(3/100)*(97/100)^2
and it worked, thank you good sir