What four weights can be used to balance from 1 to 30 pounds?

I get hot but I never sweat,
I cook food but I am not a chef,
I have a door but you can't enter me,
I have a light but I am not a lamp.
Who am I?

Can you solve below mathematical equation?

2^1234 - 2^1233

Find the next number in the sequence

1, 2, 6, 21, 88, __?

How many sides does a circle have?

A landlord calls both of his sons and tells them that their horses will now decide who will transfer the inheritance. He tells them to race along the land till the end and the one whose horse will be slower will win and be the heir to all the property.

Both of them keep wandering for days but to no result. Then they ask a wise man regarding it. The man advises them on the matter after which they jump on the horses and race as fast as they can till the end. Why did they do it?

What did the wise man say?

I’m tall when I’m young, and I’m short when I’m old. What am I?

Spot what is wrong here in below Picture?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?