Can you count the number of triangles in the given figure?

Here is a conversation between a couple who both are software professionals.

Husband: Hey! What is your date of birth?
Wife Replied Angrily: It is 591062400
Husband after doing some calculations replied, "Got It".

What is the DOB of the wife?

Thirty friends were on a hiking trip when they decided to enjoy the bonfire. They assembled for it and agreed to play a game. For that, they divided themselves into five teams with seven members each, forming five rows.

How did they manage to achieve this formation?

He runs but never walks. Murmurs, but never talks. Has a bed, but never sleeps. And has a mouth, but never eats?

Can you replace the question mark with the correct number in the below table sequence?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

Two boys wish to cross a river. The only way to get to the other side is by boat, but that boat can only take one boy at a time. The boat cannot return on its own, there are no ropes or similar tricks, yet both boys manage to cross using the boat.

How?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?