Question

The product of the means in a proportion is 20. If one of the extremes is 10, then, what is the other extreme?

• A. 5
• B. 2
• C. 10
• D. 4

Answer 1

The correct option is B 2

Let the numbers in proportion be a, b ,c ,d
When numbers are in proportion
product of the means = product of the extremes
Let the proportion be a : b : : c : d
Given that product of means i.e b$\times$c = 20 ; let a = 10

$\therefore$ b$\times$c = a$\times$d
$\Rightarrow$ 20 = 10$\times$d
$\Rightarrow$ d = 2