A race track tote board has the odds for a horse listed as 5 to 3. tote boards list the odds that a horse will lose the race. If this is the case, what is the probability of the horse winning the race?

The horse loses 5 times for every 3 it wins. Thus, the probability it loses is 5/(5+3)=5/8. So, what is the probability it wins?

If you have odd in the form a:b

The probability of 'a' occurring is

P=\frac{a}{a+b}

the probability of 'b' then occurring is 1-P