Two bar magnets A and B are placed one over the other and are...

Two bar magnets $A$ and $B$ are placed one over the other and are allowed to Vibrate in a vibration magnetometer. They make $20$ oscillations per minute when the similar poles of $A$ and $B$ are on the same side, while they make $15$ oscillations per minute when their opposite poles lie on the same side. If ${M}_{A}$ and {M}_{B}_{}are the magnetic moments of A$and$B$and if${M}_{A}> {M}_{B}$, the ratio of${M}_{A}$and${M}_{B}$\text{ and } is$