How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

A girl is twice as old as her brother and half as old as her father. In 50 years, her brother will be half as old as his father. How old is the daughter now?

No matter how little or how much you use me, you change me every month. What am I?

John and Jacob are twin brothers. One of them is a liar whereas the other one is a truth-teller.

I called their home number and one of them picked up.
I asked. 'Does John lie?' The person replied with a yes.

Whom did I talk with, John or Jacob?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?

Three brothers Jacob, John, and James live in Mexico City. The product of the ages of these brothers is 175. Jacob and John are twins. How old is James?

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

Can you fill the blank with the correct number?

6 30 870 756030 _____

Below toothpicks/matchsticks indicate the group of fishes moving from west to east direction. Can you make them move from east to west by just moving three toothpicks/matchsticks?