Question

Amber's birthday party will cost 12 if she invites 4 guests. If there are 7 guests, how much will Amber's birthday party cost (c)? Assume the relationship is directly proportional.

1) 18
2) 21
3) 24
4) 28

Answer 1

Amber's birthday party will cost $21 if she invites 7 guests.

Step-by-step explanation:

In this case, we have a direct proportion between the number of guests and the cost of the birthday party. To find out how much the party will cost with 7 guests, we can set up a proportion.

First, we write the proportion with the given values:

4 guests / $12 = 7 guests / x

Next, we cross-multiply and solve for x:

4x = 7 * $12

x = (7 * $12) / 4

x = $21

Therefore, Amber's birthday party will cost $21 if she invites 7 guests.