Question

If 3 suspects who committed a burglary and 9 innocent persons are lined up what is the probability that a witness who is not sure and has to pick 3 persons will

a. pick the three suspects by chance?



b. pick three innocent people by chance?
If 3 suspects who committed a burglary and 9 innocent persons are lined up what is the probability that a witness who is not sure and has to pick 3 persons will

a. pick the three suspects by chance?



b. pick three innocent people by chance?
@Mathematics

Answer 1

first we find the probability that they finger all three guilty "suspects"

Answer 2

has to pick first, then second then third correctly, so
\[\frac{3}{9}\times \frac{2}{8}\times \frac{1}{7}\]

Answer 3

lather, rinse, repeat