Question

An arrangement of billiard ball has 5 balls in the row and 16 rows in all. In each successive row one ball is added. What is the explicit rule for this situation, and how many will be in the 16th row?​

Answer 1

Explanation:

use arithmetic progression for solving this type of questions

see explanation

Answer 2

explicit rule is: an=4+n

number of balls: 20

Explanation:

just took the test