If the probability of an event happening is 70%, what are the odds of the event happening?

a)

7: 10

b)

7: 3

c)

10: 7

d)

3: 7

a) 7:10

Step-by-step explanation:

An example of this would be having seven blue marbles and three red marbles in a jar.  If you randomly select one, the chance of that marble being blue is seventy, because 10 (total number of marbles) divided by seven (number of blue marbles) is 0.70, and if you convert this to a whole number (by multiplying it by 100) you get 70.