Magnetism And Matter

A compass needle oscillates 20 times per minute at a place where the dip is \(45^{\circ}\) and the magnetic field is \(B_1\). The same needle oscillates 30 times per minute at a place where the dip is \(30^{\circ}\) and magnetic field is \(B_2\). Then, \(B_1: B_2\) is