Question

a cog company produces 20 cogs a day, 4 of which are defective. Find the probability of selecting 4 cogs from the 20 produced where all are defective?

Answer 1

Answer:

1/4845

Step-by-step explanation:

The probability of selecting a defective cog first is

1/5

The second cog is

3/19

The third cog is

1/9

And the fourth cog is

1/17

Multiplying these together we get

1/5 * 3/19* 1/9 * 1/17  = 1/4845