A bob of mass ' m ' suspended by a thread of length $l$ undergoes simple harmonic oscillations with time period T . If the bob is immersed in a liquid that has density $\frac{1}{4}$ times that of the bob and the length of the thread is increased by $1 / 3^{\mathrm{rd}}$ of the original length, then the time period of the simple harmonic oscillations will be :-