Which Number is the odd one out?

A) 7145
B) 2716
C) 5321
D) 4135

A man stands on one side of a river, his dog on the other. The man calls his dog, who immediately crosses the river without getting wet and without using a bridge or a boat. How did the dog do it?

Can you write down eight eights so that they add up to one thousand?

Can you find a five letter word that is left with only two letters if one is removed?

Which country gets ill every time?

Given that

(78)^9 = 6
And (69)^4 = 11

Can you find out

(99)^2 =?

(Note: This is Logical, not Mathematical)

You board a train. The train will have to enter a tunnel soon. You are claustrophobic. Which place is the best for you to sit?

John can place six large boxes or nine small boxes into a carton.

Can you find out in how many cartons can he place sixty-six boxes in total?

There is a box in which distinct numbered balls have been kept. You have to pick two balls randomly from the lot.

If someone is offering you a 2 to 1 odds that the numbers will be relatively prime, for example
If the balls you picked had the numbers 6 and 13, you lose $1.
If the balls you picked had the numbers 5 and 25, you win $2.

Will you accept that bet?

What does it mean?