Solution:

5 => FIVE

Half of five => Remove 2 letters out of 4 i.e Remove letter 'F' AND 'E'.
It remains, 'IV'
The Roman value of 'IV' is 4.

Solution:

Plates and cutlery

Solution:

Q = 1
U = 9
I = 6
C = 8
K = 3.

Explanation:
Replace values in( Q + U + I + C + K)^3 = QUICK
(1+9+8+6+3)^3 = 19863
27^3 = 19863
19863 = 19863

Solution:

Safety In Numbers

Explanation:
The word "Safety" is embedded with random numbers.

Solution:

1000$ - (Profit he earned in antique watch)

Solution:

121

Explanation
Tables consist of squares of the number from 4 to 12.
11^2 = 121.

Solution:

It can be done as shown below.

Solution:

Grid 5.

Explanation:
If you arrange the images as shown in the below image, you will notice that they all are connecting images.

Solution:

It can be done as shown in the picture below.

Solution:

The circled owl is looking away from the rest and hence antisocial.