78.1k views
0 votes
We roll two standard six-sided dice. Find the probability of the following events, assuming that the outcomes of the rolls are independent.

a) The two dice show the same number.
b) The number that appears on the first die is larger than the number on the second.
c) The sum of the dice is even.
d) The product of the dice is a perfect square.

1 Answer

4 votes

Final answer:

When rolling two six-sided dice, the probabilities are as follows: a) dice show the same number is 1/6, b) first die showing a larger number than the second is 5/12, c) sum of the dice is even is 1/2, and d) product is a perfect square is 7/36.

Step-by-step explanation:

We are looking at the probabilities of several events when two six-sided dice are rolled. Here's a step-by-step explanation:

  • a) The probability of two dice showing the same number: There are 6 possible ways this can happen (both dice showing 1, both showing 2, ..., both showing 6), out of 36 total possible outcomes (6 choices for the first die multiplied by 6 choices for the second die). Therefore, the probability is 6/36 or 1/6.
  • b) The probability of the first die showing a larger number than the second: There are 15 possible outcomes for this event (2-1, 3-1, 3-2, ..., 6-5). So the probability is 15/36, which simplifies to 5/12.
  • c) The probability that the sum of the dice is even: An even sum occurs when both dice are either even (even + even = even) or odd (odd + odd = even). There are 3 even and 3 odd numbers on a die, so there are 3*3 + 3*3 = 18 possible outcomes out of 36, giving a probability of 1/2.
  • d) The probability that the product of the dice is a perfect square: The perfect square products from two dice are 1 (1x1), 4 (1x4 or 2x2), 9 (1x9 or 3x3), 16 (2x8 or 4x4), 25 (5x5), and 36 (6x6). Counting each pair of factors gives us 7 successful outcomes out of 36 possible outcomes, so the probability is 7/36.
User Dmytro Yashkir
by
8.1k points