Question

The arithmetic mean and geometric mean of two numbers are 7 and 2√10 respectively, then find the numbers.

• A. 2, 20
• B. 5, 4
• C. 4,10
• D. 8, 5

Answer 1

Answer:

C. 4,10

Let the two numbers be a and b.

According to the question

(a + b) / 2 = 7

$\Rightarrow (a + b) = 14 $------(1)

$\sqrt{ab} = 2\sqrt{10}$

$\Rightarrow ab = 4 \times 10$

$\Rightarrow ab = 40 $----------(2)

From option, Put a = 4 and b = 10

then the condition is satisfied. So, the two numbers are 4 and 10.