Find two different velocities for which the speed is 16 feet per second.

Speed is a scalar quantity, where as vector is a vector quantity.

For example let us take a particle which moves in positive direction with speed 16 feet per sec, its velocity also 16 ft/sec since the particle is moving in positive direction (positive x-axis).

If the particle moves in negative direction with same speed 16 feet per sec,

its velocity is - 16 feet per sec.

Hence the 2 velocities for which speed is 16 feet per sec are + 16 feet per sec and - 16 feet per sec.