Question

There are 2 books on the first shelf,6books on the second shelf,12 books on the third shelf and 20 books on the the fourth shelf how many books on the tenth shelf. What do I do i need help

Answer 1

let's look to see if we can find a pattern

1-2 >>> 1x2
2-6 >>> 2x3
3-12 >>>3x4
4-20 >>> 4x5
...
looks like if n is the shelf number, then the number of books is n(n+1)

so on the 10th shelf, there would be 10x11 or 110 books

Sure hope that bookshelf is strong.