If 1+9+8=1, what is 2+8+9?

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

Solve the equation by replacing the alphabet with numbers.

MOM + MOM + NO = BOOK=

You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different. How do you measure 45 minutes?

Which is heavier: a ton of bricks or a ton of feathers?

The LCD device should be able to tell the right time in the format HH:MM: SS in a 12-hour format. You can refer to the picture to get an idea. The device is a simple "level indicator" which has to be converted into a watch. How will you program it to work?

In a family supper, a grandfather, a grandmother, two fathers, two mothers, four children, three grandchildren, one brother, two sisters, two sons, two daughters, one daughter-in-law, and one mother-in-law need to sit at a table.

There are only seven chairs available at the place. How many more chairs do they have to borrow so that everyone can sit down together for the suppers if everybody requires a separate chair?

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

Open a Laptop which is password protected. Hint for the password is given as below:

1 mobile 3 books 2 Boards 1 night 4 balls 2 lighters 1 ghost 1 hat 3 watches

On rolling two dices (six-sided normal dice) together, what is the probability that the first one comes up with a 2 and the second one comes up with a 5?