Can you fill the blank with the correct number?

6 30 870 756030 _____

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

Find the number of squares in the below-given picture.

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

If a wheel has 54 spokes, how many spaces are there between the spokes?

Christina is practising her dance steps along with her friends. In a particular sequence, all of them form a row. At that point, Niharika is standing in the 4th position from either end of the row.
Can you find out how many girls are practising together?

How many times in a given day, minutes and hour clock comes in a straight line ?

There are two arch enemies Messi and Ronaldo who hate each other to an extreme. One day both were going together and a Jeanie appeared in front of them. Jeanie grants 3 wishes to Ronaldo and one to Messi.

Messi replied smartly 'Give me twice whatever Ronaldo demands'.

Ronaldo asked his 1st wish 'Give me 10000 billion dollars. Soon Messi gets 2000 billion dollars.
Ronaldo asked for his 2nd wish 'Give me one mansion in every country in the world. Soon Messi gets two mansions in every country of the world?

What should be Ronaldo's third wish?

What has no start, end, or centre?

what does the below math rebus puzzle mean?