I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

A gardener planted the Lemon trees in a mathematical ordered way (i.e. he planted a tree in rows).
He created a total of 19 rows of trees.

Note: There should be more than 2 trees to count as a row.

What is the minimum number of trees required by the gardener to have 19 rows of trees?

Can you divide the below-given shape into four equal and identical pieces?

The doctor advised his patient to take a tablet after every fifteen minutes. He gave him five tablets in total.

How much time will he take to have all the five tablets?

Who can jump higher than a Mountain?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

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?

Move three sticks of the spiral below to form a square.

With the help clues provided in the image, can you find the 5 digit key?