Question

In a library there are certain number of books and

they are stacked in layers on a self each layer of books

has one less than the layer below it. If there are 20 books

on the bottom layer and one on the top layer. How many

books are stacked on the self?

a)210 b)120 c)420 d)105​

Answer 1

Answer:

(c) 420

Step-by-step explanation:

i had calculated book on each shelf it became this.....420