perm&comb,prob..

[romitvsingh]

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?

(A) 5 C 3
(B) 5 P 3
(C) 53
(D) 35
(E) 25
pls explain in detail

[neelgandham]

The first letter can be posted in any of the 3 post boxes.Therefore the number of choices is 3. In the same way, the second, the third, the fourth and the fifth letter can each be posted in any of the 3 post boxes.Therefore, the total number of ways the 5 letters can be posted in 3 boxes is 3*3*3*3*3
= 3^5

if option (D)35 is 3^5 then D is the answer

[Anurag@Gurome]

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?

(A) 5 C 3
(B) 5 P 3
(C) 53
(D) 35
(E) 25
pls explain in detail

The first letter can be posted in any of the 3 post boxes.oSO, it has 3 choices.
In the same way, the 2nd, 3rd, 4th and 5th letter can each be posted in any of the 3 post boxes.
Therefore, the total number of ways the 5 letters can be posted in 3 boxes is 3 * 3 * 3 * 3 * 3
= 3^5
The correct answer is D.