You toss two dice 1000 times How many times do you expect to have the sum of the two dice equal to 7?

There are two dice with 6 side each. The probability of any single unique outcome is 1/6 * 1/6 = 1/36

Now the question becomes how many ways can you roll a 7 using two dice. It might be easiest to just show this as a table:

1 6

2 5

3 4

4 3

5 2

6 1

So there are 6 ways to roll a 7 using two dice. That means the probability of rolling a 7 is 6/36 = 1/6.

Finally, to answer the question, we will multiply the probability of success (getting 7) with the number of attempts (how many times you rolled the dice). This equals 1/6 * 1000 = 166.66... or in real-life terms: 167 (remember that in real life no-one has 2.5 children)