Two vertical harmonic oscillators $($ A and $B)$ are created by attaching two

blocks with different masses to two identical springs. When the blocks are

displaced from their equilibrium position by the same distance and released,

the frequency of oscillator $A$ is measured to be three times the frequency of

oscillator $B(f_A=3f_B).$

$($a$)$ If the mass of the block in oscillator $A$ is

$,$ what is the mass

of the block in oscillator B$?$