In the school cafeteria students chose their lunch from 3 sandwiches, 3 soups, 4 salads, and 2 drinks. how many different lunches are possible for a student who chooses exactly 1 sandwich, 1 soup, 1 salad, and 1 drink?

3

×

3

×

4

×

2

=

72

Explanation:

Let's look at the 3 sandwiches and 3 soups first and then expand the calculation. There are 9 ways I can have one of the sandwiches and 1 of the soups:

⎛

⎜

⎜

⎜

⎜

⎝

0

Soup 1

Soup 2

Soup 3

Sandwich 1

1

2

3

Sandwich 2

4

5

6

Sandwich 3

7

8

9

⎞

⎟

⎟

⎟

⎟

⎠

And so we can see that we multiply the number of sandwiches and the number of soups to get the total number of ways to get one of each.

The same works for more categories of choices, and so we multiply the 3 sandwiches, the 3 soups, 4 salads, and 2 drinks to get:

3

×

3

×

4

×

2

=

72

answer

explanation

the area of a circle is calculated using the formula

or

we can use any of the above formulae to calculate the required. preferably, let us use the latter since the diameter is

we substitute the diameter into the formula to get:

this is the exact value for the area of the circle.

the correct answer is a