A horse race has 13 entries and one person owns 3 of those horses. Assuming that there are no ties, what is the probability that those three horses finish first comma second and third (regardless of order)?

answer:

c(11,4) = 11! / (4! * 7!) = (11 * 10 * 9 * 8 * 7!) / (4! * 7!) = (11 * 10 * 9 * 8) / (4 * 3 * 2 * 1) = 330.

Step-by-step explanation:

δabc ≅ δdcb by sas because

db ≅ ac . . given (side)

bc ≅ bc . . reflexive property (side)

∠dbc ≅ ∠ acb . . alternate interior angles where transversal bc crosses parallel lines bd and ac (included angle)

it would open into a square depending on the type of envelope i’m not sure about the second part