Question

A man on tour travels first 160 km at 64 km/hr and the next 160 km at 80 km/hr. The average speed for the first 320 km of the tour is:

• A. 71.11 km/hr
• B. 35.55 km/hr
• C. 36 km/hr
• D. 77 km/hr

Answer 1

Answer: (A)

Total time taken $=(\frac{160}{64}+\frac{160}{80})hrs.=\frac{9}{2}rs.$
$\therefore$ Average speed =$(320\times \frac{2}{9})$ km/hr= 71.11 km/hr.