If the radii of the circles and are increasing uniformly w.r.t

MATHEMATICS · Single correct · AP · Calculus AB · Contextual Applications of Differentiation · Contextual Applications of Differentiation

Problem

If the radii of the circles

(x-1)^2 + (y-2)^2 = 1

and

(x-7)^2 + (y-10)^2 = 4

are increasing uniformly w.r.t. time as 0.3 unit/s and 0.4 unit/s respectively, then they will touch each other at

t

equals to (1) 45 s (2) 90 s (3) 11 s (4) 135 s