Ahouse has a large window made of 15 equal-sized pieces of glass, each the same size and shape. there are 3 pieces of glass that are cracked. if a rock thrown by a lawn mower hits the window, what is the probability that the rock hits a piece of glass that is cracked?

The chance or probability that the lawn mower will hit a piece of glass that is already cracked is calculated by dividing the number of glasses that are cracked by the total number of glasses. In this item, the unknown can be calculated by 3/15. The answer is therefore, 1/5 or 0.20.