In horseracing, an “Exacta” bet is won by correctly predicting the horses that finish first and second. Also, the horses must be selected in the correct order. A recent horserace had a field of 20...

In horseracing, an “Exacta” bet is won by correctly
predicting the horses that finish first and second.
Also, the horses must be selected in the correct
order. A recent horserace had a field of 20 horses. If
you randomly select two of the twenty for an Exacta
bet, what is your probability of winning?