If a car travels $40 \%$ of the total distance with a speed $v_1$ and the remaining distance with a speed $\mathrm{v}_2$, then average speed of the car is

• A

  $\frac{1}{2} \sqrt{\mathrm{v}_1 \mathrm{v}_2}$
• B

  $\frac{v_1+v_2}{2}$
• C

  $\frac{2 v_1 v_2}{v_1+v_2}$
• Correct answer
  D

  $\frac{5 v_1 v_2}{3 v_1+2 v_2}$

Hence, the correct answer is option: 'D'.