Maria sold 10kg of apples in her first hour at the market, but only 2kg of apples in the second hour. On average, how many kg of apples did she sell in two hours at the market?	Pick.
A) 6 kg B) 5 kg C) 12 kg D) 24 kg E) 20 kg

Rationale: ( 10 kg + 2 kg ) / 2 = 6 kg correct answer is : a
Answer: A