Mathematics

Problem

The set of all real values of

\lambda

for which exactly two common tangents can be drawn to the circles

x^2 + y^2 - 4x - 4y + 6 = 0

and

x^2 + y^2 - 10x - 10y + \lambda = 0

is the interval : (1) (18, 48) (2) (12, 24) (3) (18, 42) (4) (12, 32)