Correct Answer - Option 3 :
1/90
Given:
HCF = 3
LCM = 90
Calculation:
Let assume the number be 3a
and the second number be 3b
According to question:
3a + 3b = 33
⇒ a + b = 11 ----(1)
LCM od 3a and 3b = 3ab
So, 3ab = 90
⇒ ab = 30 ----(2)
From equation (1) and equation (2)
a = 5
b = 6
⇒ The first number is = 3a = 3 × 5 = 15
⇒ The second number is = 3b = 3 × 6 = 18
The difference of reciprocal of numbers
⇒ 1/15 - 1/18 = 1/90