Question

The graph below shows a relationship between the number of items sold with respect to time (in min).
For which parts the sales number is increasing with respect to time?

• A. B, E
• B. A, C
• C. D, F
• D. C, D

Answer 1

The correct option is B A, C


Let's consider Part A of the graph:

Time (in min)	Number of items sold
0	0
1	5

Number of items sold increases with respect to time.

Hence, Part A of the graph represents an increasing function.

Let's consider Part B of the graph:

Time (in min)	Number of items sold
1	5
2	5

Number of items sold is constant with respect to time.

Hence, Part B of the graph represents a constant function.

Let's consider Part C of the graph:

Time (in min)	Number of items sold
2	5
3	10

Number of items sold increases with respect to time.

Hence, Part C of the graph represents an increasing function.

Let's consider Part D of the graph:

Time (in min)	Number of items sold
3	10
4	5

Number of items sold decreases with respect to time.

Hence, Part D of the graph represents a decreasing function.

Let's consider Part E of the graph:

Time (in min)	Number of items sold
4	5
5	5

Number of items sold is constant with respect to time.

Hence, Part E of the graph represents a constant function.

Let's consider Part F of the graph:

Time (in min)	Number of items sold
5	5
6	0

Number of items sold decreases with respect to time.

Hence, Part F of the graph represents a decreasing function.

Let's consider Part G of the graph:

Time (in min)	Number of items sold
6	0
7	0

Number of items sold is constant with respect to time.

Hence, Part G of the graph represents a constant function.

Tabulating the different parts of the graph, we observe:

Part of the graph	Function represented by the part
A	Increasing
B	Constant
C	Increasing
D	Decreasing
E	Constant
F	Decreasing
G	Constant

Therefore, Part A and Part C of the graph represent increasing function.