Mathematics

Problem

Two cyclists start from the junction of two perpendicular roads, their velocities being

3v\,\text{m/min}

and

4v\,\text{m/min}

. The rate at which the two cyclists are separating is: (a)

\frac{7}{2}v\,\text{m/min}

(b)

5v\,\text{m/min}

(c)

v\,\text{m/min}

(d)

7v\,\text{m/min}