A bag contains 8 oranges, 9 pears and 13 apples. What is the probability a pear is picked?

The probability of an event happening is defined as the number of outcomes you're looking for (in this example the number of pears, 9) divided by the total number of outcomes (i.e. the total number of fruit in the bag, 8+9+13 = 30). This gives our probability as 9/30 which can be simplified down to 3/10 or 0.3.