Question

Please help with probability. I'm really bad at it and I really need to study this but I can't work around the problem. Help please. Thank you so much.

If a safety switch has a 1 in 10 chance of failing, how many switches would a company want to install in order to have only a 1 in one million chance of them all failing at the same time? Show your reasoning.

Answer 1

P(1) = 1/10
P(1 AND 2 AND 3 AND....n) = 1/1000000
n = ?

Answer 2

Would it be 1/10•1/10•1/10 ?

Answer 3

if it helps
P(1 AND 2 AND 3 AND....n) = 1/1000000
P (1) = 1/10
P (2) = 1/10
P (3) = 1/10

so P(1 AND 2 AND 3) = P(1) x P(2) x P(3)
= 1/10 x 1/10 x 1/10
= (1/10)^3
= 1/1000

note... 1/1000000 = (1/10)^6

Answer 4

No 1/10•1/10•1/10•1/10•1/10•1/10

6?

Answer 5

Okay I understand hat so would the answer be 6?