The graph shows the relationship between the total cost and the number of gift cards that Raj bought for raffle prizes.

A graph titled Cost of Gift Cards. The x-axis shows the number of gift cards, numbered 1 to 9, and the y-axis shows the total cost in dollars, numbered 10 to 90. Blue diamonds appear at points (1, 20), (2, 40), (3, 60), (4, 80).
What would be the cost for 5 of the gift cards?

$80
$90
$100
$110

1 answer

To determine the cost for 5 gift cards, we can analyze the pattern in the graph.

Given points on the graph are:
- (1, 20)
- (2, 40)
- (3, 60)
- (4, 80)

Observing the points, we notice that for each increase of 1 gift card, the total cost increases by $20. The relationship between the number of gift cards (x) and the total cost (y) can be expressed as:

\[ y = 20x \]

We can predict the cost for 5 gift cards using this equation:

\[ y = 20 \times 5 = 100 \]

Therefore, the cost for 5 gift cards is $100.

The correct answer is $100.