Won't like it till you Solve it!!

A particle with a mass of 1 kg is having a velocity of 10 m $s^{-1}$ in +ve x-direction at t=0 . Forces $F_{1}$ and $F_{2}$ act on the particle whose magnitude are changing with time according to the variation shown In figure. The magnitude of the velocity of the particle at t=3 s(neglect gravity effect) is found to be n $\sqrt{5}$ m $s^{-1}$ . Find the value of n .