In how many ways can 5 letters be posted in 3 post boxes, if any number of letters can be posted in all of the three post boxes? Choose the most appropriate option.
A) 3	B) 9	C) 3^5	D) 5^3	E) 2^4
The first letter can be posted in any of the 3 post boxes. Therefore, we have 3 possibilities.   Similarly, the second, the third, the fourth and the fifth letter can each be posted in any of the 3 post boxes.   Each of the 5 letters has 3 possibilities because we can post any number of letters in all of the boxes.   Therefore, the total number of ways the 5 letters can be posted in 3 boxes is   3 * 3 * 3 * 3 * 3 = 3^5   Ans:3^5
<result>C</result>
In how many ways can 5 letters be posted in 3 post boxes, if any number of letters can be posted in all of the three post boxes?