SSC CPO 2024 PYQ — Question 130

The correct answer is option 3 i.e.  $11\frac{11}{13} km/h$

Given that

The person covers 11 km at a speed of 7 km/h

Time taken = 11 / 7 hours

He covers 25 km at a speed of 10 km/h

Time taken = 25 / 10 hours

He covers 30 km at a speed of 20 km/h

Time taken = 30 / 20 hours

Formula used 

Average speed = total distance / total time

Hence, average speed = 66 / $\frac{39}{7}$ = 66 × $\frac{7}{39}$ = $\frac{154}{13}$ = $11\frac{11}{13} km/h$.