Randomly pick a whole number between 10 and 99 (inclusive). Then multiply the digits together. What is the chance that the resulting number is even?
+23246 The ten's digit can be either an odd number (1, 3, 5, 7, 9) or an even number (2, 4, 6, 8).
The probability that this digit is odd is 4/9.
The one's digit has a probability of 5/10 to be odd and a probability of 5/10 to be even.
The only way that the product is odd is for each of the two digits to be odd. The probability that this happens is 5/9 x 1/2 = 5/18.
