Solution:

When the going gets tough, the tough get going.

Solution:

1)The first bit is easy, as the first letter of each plate spells WHODUNNIT IX(A challenge to our Detective.)
2)The second bit is a little trickier, but I gave you the solution.If you read the last three letters in each plate from the bottom up and right to left you get ADVANCE EACH LETTER BY THE NUMBER SHOWN, so advance W by 5 to get B, H by 13 to get U and so on until you spell BUTLER DID IT.

Solution:

* The first surgeon operates with the first glove (glove A) inside the
second glove (glove B).

* The second surgeon operates using just glove B.

* The third surgeon operates using glove A, turned inside out, inside glove B.

Solution:

445

2=(1+1)1
6=(2+1)2
21=(6+1)3
88=(21+1)4

So 445=(88+1)5

Solution:

Dabid is the killer

drawing room(D) , art room(a) , bed room (b) , ice-cream room (i) , desk room (d)

Solution:

10 o'clock + 4 hours = 2 o'clock.

Solution:

1. 26 L of the A (26 Letters of the Alphabet)

2. 7 D of the W (7 days of the Week)

3. 1000 Y in a M (1000 years in a millennium)

Solution:

Tennis shoes

Solution:

Newspaper delivery man was the murderer because of absence of Wednesday and Thursday missing newspaper.
This indicates he already know that there is no one to read it.

Solution:

794

The nth term in the series is given by the sum of x^n for x in the range 1 to 3, i.e. 1^n + 2^n + 3^n.

Thus the first term is 1^1 + 2^1 + 3^1 = 1 + 2 + 3 = 6,
the second term is 1^2 + 2^2 + 3^2 = 1 + 4 + 9 = 14,
and so on.

The sixth term is then 1^6 + 2^6 + 3^6 = 1 + 64 + 729 = 794.