Question: A number x is selected at a random from the numbers 1, 2, 3 and 4. Another number y is selected at random from the numbers 1, 4, 9 and 16. Find the probability that product of x and y is less than 16.
Video Explanation
Explanatory Answer
Product of x and y will be one of the following 16 values:
1, 4, 9, 16, 2, 8, 18, 32, 3, 12, 27, 48, 4, 16, 36, 64.
Of these 16 possibilities, the following values are less than 16: 1, 4, 9, 2, 8, 3, 12, 4 ⇒ 8 values.
Probability that product is less than 16
= \\frac{\text{Number of outcomes where xy is less than 16}}{\text{Total outcomes for xy}})
= \\frac{8}{16}) = \\frac{1}{2})