To get the probability of even numbers, you divide the amount of even numbers by the total amount of numbers. You should get 2 (amount of even numbers) /4 (total amount of numbers.) This simplifies to 1/2. I hope this helps and that you have a marvelous day!! Stay safe!!
It is given that there are 30 tables in total and there are two types of tables.
Let's call the two seat tables, the first type as x and the second type as y.
∴ x + y = 30 ......(1)
Also a total number of 81 people are seated. Therefore, 2x number of people would be seated on the the first type and 5y on the second type. Hence the equation becomes:
2x + 5y = 81 .....(2)
To solve (1) & (2) Multiply (1) by 2 and subtract, we get: