Solution:

30.

For Explanation, watch video

Solution:

75.

For a detailed explanation, please watch the video.

Solution:

It can be done as shown in the video below.

Solution:

D & C.

For details, Please check the video.

Solution:

51

For Explanation, Watch the video.

Solution:

38.

Watch the video for an explanation.

Solution:

405

For an explanation, watch the video.

Solution:

39.

Solution:

The hidden cat is encircled below.

Solution:

Since the beer bottle is closed, No glass will Ever fill.

The video-version of the puzzle is added below.