The graph below shows the amount of money left in the school’s desk fund, f, after d desks have been purchased.

Question

A graph titled Desk Fund Amount. The horizontal axis shows the number of desks purchased (d), numbered 1 to 9, and the vertical axis shows the dollars left in fund (f) numbered 100 to 800. Blue diamonds appear at points (0, 700), (1, 590), (2, 480), (3, 370), (4, 260), (5, 150), (6, 40).

For each new desk that is purchased, by how much does the amount of money left in the school’s desk fund decrease?

$110
$135
$165
$190

Answer 1

To determine the amount by which the money left in the school’s desk fund decreases for each new desk purchased, we need to find the difference in the amount of the fund before and after a desk is purchased. We can do this by examining any two adjacent points on the graph and calculating the difference.

First, let's look at two consecutive data points on the graph:
- When \( d = 0 \), \( f = 700 \)
- When \( d = 1 \), \( f = 590 \)

Calculate the difference:
\[ 700 - 590 = 110 \]

Next, let's verify this with another pair of consecutive points to confirm the consistency:
- When \( d = 1 \), \( f = 590 \)
- When \( d = 2 \), \( f = 480 \)

Calculate the difference:
\[ 590 - 480 = 110 \]

Thus, each time a desk is purchased, the amount of money left in the school’s desk fund decreases consistently by \( 110 \).

So, the correct answer is:
\[ \boxed{110} \]