Question

the manager of a deli counted the number of sandwiches sold each day. sandwich sales according to the graph, when was the rate of decrease greater? between monday and friday between wednesday and thursday

Explanation:

To determine when the rate of decrease was greater, we calculate the rate of decrease for different intervals. The rate of decrease is calculated as the change in the number of sandwiches sold divided by the number of days between the two points.

Step 1: Calculate the rate of decrease between Monday and Tuesday

• Sandwiches sold on Monday: \( 90 \)
• Sandwiches sold on Tuesday: \( 55 \)
• Number of days between Monday and Tuesday: \( 1 \) (since it's consecutive days)
• Change in sandwiches sold: \( 90 - 55 = 35 \)
• Rate of decrease: \( \frac{35}{1} = 35 \) sandwiches per day

Step 2: Calculate the rate of decrease between Tuesday and Wednesday

• Sandwiches sold on Tuesday: \( 55 \)
• Sandwiches sold on Wednesday: \( 55 \)
• Change in sandwiches sold: \( 55 - 55 = 0 \)
• Rate of decrease: \( \frac{0}{1} = 0 \) sandwiches per day (no decrease)

Step 3: Calculate the rate of decrease between Wednesday and Thursday

• Sandwiches sold on Wednesday: \( 55 \)
• Sandwiches sold on Thursday: \( 55 \)
• Change in sandwiches sold: \( 55 - 55 = 0 \)
• Rate of decrease: \( \frac{0}{1} = 0 \) sandwiches per day (no decrease)

Step 4: Calculate the rate of decrease between Thursday and Friday

• Sandwiches sold on Thursday: \( 55 \)
• Sandwiches sold on Friday: \( 50 \)
• Number of days between Thursday and Friday: \( 1 \)
• Change in sandwiches sold: \( 55 - 50 = 5 \)
• Rate of decrease: \( \frac{5}{1} = 5 \) sandwiches per day

Step 5: Calculate the rate of decrease between Monday and Friday

• Sandwiches sold on Monday: \( 90 \)
• Sandwiches sold on Friday: \( 50 \)
• Number of days between Monday and Friday: \( 4 \) (Monday to Tuesday is 1, Tuesday to Wednesday is 1, Wednesday to Thursday is 1, Thursday to Friday is 1; total \( 4 \) days)
• Change in sandwiches sold: \( 90 - 50 = 40 \)
• Rate of decrease: \( \frac{40}{4} = 10 \) sandwiches per day

Step 6: Compare the rates of decrease

• Rate between Monday and Tuesday: \( 35 \) sandwiches per day
• Rate between Thursday and Friday: \( 5 \) sandwiches per day
• Rate between Monday and Friday: \( 10 \) sandwiches per day

The highest rate of decrease is between Monday and Tuesday (35 sandwiches per day). However, looking at the options provided:

• "between Monday and Friday" has a rate of \( 10 \) sandwiches per day.
• "between Wednesday and Thursday" has a rate of \( 0 \) sandwiches per day (no decrease).

Since the question asks "when was the rate of decrease greater" among the given options, we compare the two options:

• Rate between Monday and Friday: \( 10 \) sandwiches per day.
• Rate between Wednesday and Thursday: \( 0 \) sandwiches per day.

So the rate of decrease is greater between Monday and Friday.

Answer:

between Monday and Friday