# When three springs are used to suspend a mass what happens to the natural frequency when compared to when each of the spring is used to suspend the same mass:

a.       Decreases b.      Increases  c.       Remains the same d.      None of the above

The three springs suspending the same mass is equivalent to strengthening each of the spring as each of the spring produces a certain restarting force.
Note that the springs are in parallel.
Thus the net spring constant is $k_1+k_2+k_3$, whereas if they are in series with only one mass at the end the springs are in series and the net spring constant is $\large\frac{k_1k_2k_3}{(k_1+k_2+k_3)}$ and hence is lesser than $k_1+k_2+k_3$ as far springs in parallel.
Hence b is the correct answer.