Answer:
The answer is "64.19".
Step-by-step explanation:
[tex]\text{Average speed = Harmonic mean speed}[/tex]
[tex]= \frac{2}{\frac{1}{60} + \frac{1}{69}}\\\\ = \frac{2}{\frac{69+60}{4,140} }\\\\ = \frac{2}{\frac{129}{4,140} }\\\\= \frac{2}{0.0311594203 }\\\\ = 64.1860465 \\\\ \bold{= 64.19}[/tex]
The final answer is "64.19".