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:

Op 1: 55/601
Op 2: 601/55
Op 3: 11/120
Op 4: 120/11

Solution:


Option: 3

HCF*LCM= Product of two numbers

Let the numbers be x and y.
Then, x + y = 55
x.y = 5*120 = 600

the sum is 1/x+1/y= (x+y)/xy

=55/600
=11/120