If the sum of two numbers is 55 and the H.C.F. and L.C.M. of these numbers are 5 and 120 respectively, then the sum of the reciprocals of the numbers is equal to:

Let the numbers be a and b.

Then, a + b = 55 and ab = 5 x 120 = 600.

The required sum = $\frac{1}{a}+\frac{1}{b}$ =  $\frac{a+b}{ab}$=  $\frac{55}{600}$= $\frac{11}{120}$