Motion In A Plane

Projectiles A and B are thrown at angles of \(45^{\circ}\) and \(60^{\circ}\) with vertical respectively from top of a \(400 \mathrm{~m}\) high tower. If their ranges and times of flight are same, the ratio of their speeds of projection \(v_A: v_B\) is :

[Take \(g=10 \mathrm{~ms}^{-2}\)]