A person travels from P to Q a speed of 80 km/hr and returns by increasing his speed by 10%. What is his average speed for both the trips?  Choices.
A) 33 B) 77 C) 48 D) 84 E) 21

Rationale: "speed on return trip = 110 % of 80 = 88 km / hr . average speed of trip = 80 + 88 / 2 = 168 / 2 = 84 km / hr answer : d"
Answer: D