Solution:

In the first deal, Sam made a profit of $250.
In the second deal, Sam made a profit of $250 again.

Therefore, he earned a total profit of $500.

Solution:

The teacher will use a simple trick to form a perfect impression. He will ask all his students to raise their hands on each of the question that is asked. But the only catch will be that those who knows the answer correctly will raise their right hand and others will raise their left hand.

In this way, the principal will see all the hands being raised for each question even though all won't be knowing the correct answer. The teacher will ask only those who know the answer and they will always be correct. So the principal will be impressed to full extent.

Solution:

Solution is shown in image below

Solution:

Either your read from start or from ends, it will be same

Solution:

This can be done if you draw a five pointed star and place the balls on the corners and intersection points. See the figure to understand better.

Solution:

A) Yes

Explanation"
There are two scenarios.

Scenario-1: Millie is married
Millie is looking at Stones(not married)

Scenario-2: Millie is not married
Terry(married) is looking at Millie

Solution:

The Lady sitting in the chair has the detector attached to the back of her blouse.

Solution:

If two widows, each having a son married the son of the other widow, and then by the consummation of marriage, both the couples had a daughter, all the aforementioned relationships will turn to be true.

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:

LOTTO

Explanation:
Just flip the two rows 1 and 2 vertically, you will find the word "Lotto".

Solution:

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