Q9. The average (arithmetic mean) of... [FREE SOLUTION]

Chapter 2: Q9. (page 106)

The average (arithmetic mean) of r, s, x and y is 8, and the average of x and y is 4. What is the average of r and s?
$\begin{array}{l} A . 4B.6 \\ C . 8D.12 \end{array}$

Short Answer

Expert verified

The average of r and s is12. Option D is correct.

Step by step solution

Step-1 – Apply the concept of arithmetic mean

The arithmetic mean or average of numbers $x_{1}, x_{2}, 鈥� x_{n}$ is sum of the numbers divided by total count of numbers n. Mathematically, it is expressed below.

$\overset{炉}{x} = \frac{x_{1} + x_{2} + 鈥� + x_{n}}{n}$

Step-2 –Express the data from question

Consider the provided information that average of four numbers r, s, x, and y is 8.

Also, average of x and y is 4.

Express the average of r, s, x, and y as shown below.

$\frac{r + s + x + y}{4} = 8$

Multiply both sides by 4.

$r + s + x + y = 32$

Express the average x and y as shown below.

$\frac{x + y}{2} = 4$

Multiply both sides by 2.

$x + y = 8$

Step-3 – Compute average of r and s

The average of r and s is expressed as $\frac{r + s}{2}$ .

Substitute $x + y = 8$ in the equation $r + s + x + y = 32$ and simplify.

\begin{matrix} r + s + 8 = 32 \\ r + s = 32 鈭� 8 \\ r + s = 24 \end{matrix}

Divide both sides by 2.

$\frac{r + s}{2} = 12$

Hence, the average of r and s is 12.

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The average (arithmetic mean) of r, s, x and y is 8, and the average of x and y is 4. What is the average of r and s?
$\begin{array}{l} A . 4B.6 \\ C . 8D.12 \end{array}$

Short Answer

Step by step solution

Step-1 – Apply the concept of arithmetic mean

Step-2 –Express the data from question

Step-3 – Compute average of r and s

One App. One Place for Learning.

Most popular questions from this chapter

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91影视

The average (arithmetic mean) of r, s, x and y is 8, and the average of x and y is 4. What is the average of r and s?A.4B.6C.8D.12

Short Answer

Step by step solution

Step-1 – Apply the concept of arithmetic mean

Step-2 –Express the data from question

Step-3 – Compute average of r and s

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Math Textbooks

Discrete Mathematics

Logic and Functions

Theoretical and Mathematical Physics

Probability and Statistics

Calculus

Geometry

Study anywhere. Anytime. Across all devices.

The average (arithmetic mean) of r, s, x and y is 8, and the average of x and y is 4. What is the average of r and s?
$\begin{array}{l} A . 4B.6 \\ C . 8D.12 \end{array}$