Solution:

I have written 'your exact weight' on the paper.

Solution:

One Night Stand.

Explanation:
Number 'One' + Knight(chess piece) + st + and(symbol &)

Solution:

888 + 88 + 8 + 8 + 8 = 1000

Solution:

Costa

Explanation:
c + 1 characters-> d
o + 2 characters-> q
s + 3 characters-> v
t + 4 characters-> x
a + 5 characters-> f

=> dqvxf = costa

Solution:

If you see the picture, they formed a pentagonal shape and achieved the required.

Solution:

At every floor, the detective had to open the window himself. If the man had committed suicide, then at least one of the windows must have been open. A person who is committing suicide won’t close the window behind him. Thus he knows that someone pushed him off the edge and closed the window afterwards.

Solution:

What must be kept in mind before you start calculating through any method is that the weights can be put on both the pans.

So the weights - 1, 3, 7, 12, 43, 76, 102

The oldest man that can be weighed using these weights is a man aged 122 years

Solution:

28 =>1+2+4+7+14

cannot be 1 (as number cannot be included)

Solution:

See the figure for the answer. Wasn't it a bit tricky?

Solution:

Pages 19, 20, 23, 37, 38, & 42 will also be missing

Solution:

Can be found on the pic below.