This table shows how the cost of Paco's birthday party depends on the number of guests.

Question

​
​Cost of Paco's birthday party:
​Guests, x
​4 8​ ​12
​Cost, x
​20 ​40 ​ ?

​Determine the cost of having
12 guests at the party.
A
The relationship is not directly proportional.
B
$60
C
$80
D
$120

Answer 1

To determine the cost of having 12 guests at the party, we can analyze the costs given for 4 and 8 guests to identify the pattern.

We have the following data:

• For 4 guests: $20
• For 8 guests: $40

Let's calculate the cost per guest:

1. For 4 guests: \[ \text{Cost per guest} = \frac{20}{4} = 5 \text{ dollars per guest} \]

2. For 8 guests: \[ \text{Cost per guest} = \frac{40}{8} = 5 \text{ dollars per guest} \]

From this, we can see that the cost per guest is consistent and equals $5.

Now, to find the cost for 12 guests: \[ \text{Cost for 12 guests} = 12 \times 5 = 60 \text{ dollars} \]

So the cost of having 12 guests at the party is $60, which corresponds to option B.

Thus, the answer is:

B: $60