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

You are on a Boat in the mid of a river. You have two cigarettes with you. One of these two you have to light, how will you light the cigarette?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

What does this Rebus Picture means ?

Four friends are sitting on a tree. Each one of them is wearing a hat. They don't know which coloured hat are they wearing but they do know that two of them have green hats and two of them have orange hats.

Adam is sitting on the top branch and he can see the hats of Billy and Cyrus. Billy is sitting on a branch above Cyrus and he can see Cyrus hat. Duke is sitting at the base of the tree. Branches are covering him fully and no one can see his hat.

Now they are not allowed to look upwards. Who do you think will shout the colour of his hat first?

John can eat 27 chocolates in an hour, Jacob can eat 2 chocolates in 10 minutes, and Jolly can eat 7 chocolates in 20 minutes. How long will it take them to share and eat a box of 120 chocolates whilst playing Chess?

When it is alive we sing, when it is dead we clap our hands. What is it?

A quarter is one-fourth of a dollar but Mr. John has changed the equation as below :

DOLLAR * 4 = QUARTER

Can you replace each letter with a digit to make the above solution correct?

The Federal bank of London is abducted by the robbers. The head of the robbers asked the cashier to empty their money vault to them and when suddenly cashier got a call from her father. To avoid any suspicion, the robber asked the cashier to pick the call and reply her father in the shortest manner possible.

The cashier told her father "Is there an emergency father, Call me when you are free and I will help you in your furnishing" and then the cashier hung up the phone.

After 10 minutes, police arrived at the crime scene.

How did the police know about the robbery?

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?