Can you fill the blank with the correct number?

6 30 870 756030 _____

How can you tell a raw egg from a hard-boiled egg?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

They are three errirs in this question. Can you find them?

In the image below, you can see two glasses and two matchsticks.You need to move four matchsticks in such a manner that the crosses come inside the glasses. Note: you cannot move the crossed.

The day after tomorrow will be three days before Tuesday. Can you find out what is today?

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

A patient was diagnosed with some ailment. He was given five different tablets to take at night at an interval of 15 minutes.

How long will it take the patient to consume all the five tablets?

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?

What is next number in the pattern below:

131 517 192 123 ?