If the average of two numbers is 13 and the square root of their product is 12, then the difference between the numbers is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 10
Let the two numbers a and b
Given, (a + b)/2 = 13
⇒ a + b = 26
Also, (ab)1/2 = 12
⇒ ab = 144
We know, (a - b)2 = (a + b)2 - 4ab
⇒ (a - b)2 = 262 - 4 × 144
⇒ (a - b)2 = 676 - 576
⇒ (a - b)2 = 100
⇒ (a - b) = 10