A 0.56-kg mass is suspended from a string, forming a pendulum. The period of this pendulum is 3.6 s when the amplitude is 2.2 cm. The mass of the pendulum is now reduced to 0.27 kg. What is the period of oscillation now, when the amplitude is 2.5 cm? Give answer in seconds.

I was thinking that T is not dependant upon mass. I was using the equation T= (2*pi)*( sqrt L/g) =
(2pi)*(sqrt2.5/9.8) = 3.17 which is wrong.