It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

Count the squares in the matchstick puzzle below?

The dirtier I get, the whiter I look. Who am I?

It is deaf, Dumb and Blind!!!

Still, always tells the truth. What is it?

Can you find out the total number of triangles in the given figure?

Can you solve the below algebraic mathematical equation?

(J+O+I+N+T)3 = JOINT

After teaching his class all about Roman numerals (X = 10, IX=9 and so on) the teacher asked his class to draw a single continuous line and turn IX into 6. The teacher's only stipulation was that the pen could not be lifted from the paper until the line was complete.

There are three identical triplets sisters. Demi is the oldest of them all and she always speaks the truth. Diana is the next one who is a liar always. Drew, the youngest of them all speaks both truth and lies randomly.

On a rainy day, a family friend Victor visited them. Since there were starkly identical, he was not able to recognize them. Thus to clarify, he asked one question to each one of them.

He started with the one standing on the left and asked, 'Which sister is in the middle of you three?' She answered, 'That's Demi.'

Then, he asked the one standing in the middle, 'What is your name?' She answered, 'I am Drew.'

Finally, he asked the one standing on the right, 'Who is standing in the middle?' She answered, 'She is Diana.'

Victor was left baffled. He asked the questions three times and received different answers every time.

Can you tell who was who?

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?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?