Question

The given table shows the relationship between the number of students (s) in a class and the number of desks needed (n). Which of the following statements about the table are correct?

$\begin{array}{ccccc}\text{Number of}& 30& 40& 50& 60\\ \text{students (s)}& & & & \\ \text{Number of}& 15& 20& 25& 30\\ \text{desks needed (n)}& & & & \end{array}$

Statement 1: n is a dependent variable and s is an independent variable.
Statement 2: n is an independent variable and s is a dependent variable.
Statement 3: n is always twice of s. Statement 4: n is always half of s.

• A. Only statement 1 is correct.
• B. Only statement 3 is correct.
• C. Both statement 2 and statement 4 are correct.
• D. Both statement 1 and statement 4 are correct.

Answer 1

The correct option is D Both statement 1 and statement 4 are correct.

The number of desks needed (n) depends on the number of students (n) in a class.
Hence, the number of desks needed (n) is a dependent variable and students (n) is an independent variable.
In the given table, the number of desks needed (n) is always half the number of students (s) in the class.

$$\begin{array}{ccccc}\text{Number of}& 30& 40& 50& 60\\ \text{studnets (s)}& & & & \\ \text{Number of}& 30÷2=& 40÷2=& 50÷2=& 60÷2=\\ \text{needed (n)}& 15& 20& 25& 30\end{array}$$ Hence, statement 1 and statement 4 are correct.