Rahim bought 4 pillows with the average cost of $5. If Rahim also buys the fifth pillow with the price of $ 10, what is the average (arithmetic mean) price of those 5 pillows? Choose the correct choice from the following options:
A) $ 6	B) $ 5	C) $ 5.5	D) $ 6.5	E) $ 7

Rationale: 4 pillowss - > total cost = 4 * avg cost = 4 * 5 = 20 fifth pillow cost = 10 total cost for 5 pillows = 20 + 10 = 30 am = 30 / 5 = 6 hence a
Answer: A