fallenshadow

May 20th, 2012, 04:23 PM

Hi guys/gals,

Recently I have found that I have forgotten how to do simple enough maths problems relating to probablity and statistics.

I would appreciate if someone could help me out.

Machines A, B, C produce respectively 20, 30 and 50 percent of the total output. Of their respective outputs 5, 3 and 2 percent are defective. An item is chosen at random.

1. What is the probablity that it is defective?

2. If the item is defective, what is the probability it was produced by machine A?

Does this need a formula or can these be figured out with simple logical math?

Recently I have found that I have forgotten how to do simple enough maths problems relating to probablity and statistics.

I would appreciate if someone could help me out.

Machines A, B, C produce respectively 20, 30 and 50 percent of the total output. Of their respective outputs 5, 3 and 2 percent are defective. An item is chosen at random.

1. What is the probablity that it is defective?

2. If the item is defective, what is the probability it was produced by machine A?

Does this need a formula or can these be figured out with simple logical math?