If the body covers one-third distance at speed v1, next one third at speed v2 and last one third at speed v3, then average speed will be

(1) $\frac{{v}_{1}\text{\hspace{0.17em}}{v}_{2}+{v}_{2}\text{\hspace{0.17em}}{v}_{3}+{v}_{3}\text{\hspace{0.17em}}{v}_{1}}{{v}_{1}+{v}_{2}+{v}_{3}}$

(2) $\frac{{v}_{1}+{v}_{2}+{v}_{3}}{3}$

(3) $\frac{{v}_{1}{v}_{2}{v}_{3}}{{v}_{1}\text{\hspace{0.17em}}{v}_{2}+{v}_{2}\text{\hspace{0.17em}}{v}_{3}+{v}_{3}\text{\hspace{0.17em}}{v}_{1}}$

(4) $\frac{3{v}_{1}{v}_{2}{v}_{3}}{{v}_{1}\text{\hspace{0.17em}}{v}_{2}+{v}_{2}\text{\hspace{0.17em}}{v}_{3}+{v}_{3}\text{\hspace{0.17em}}{v}_{1}}$