Chapter # 4: Sequences and Series # Exercise # 4.2: Question # 9, Question # 10 and Question # 11:~

#Question # 9:

In this question, the distances covered by a body in successive seconds are given and it is observed that the distance decreases by a constant amount each second. Since the difference between consecutive terms is constant, the given distances form an arithmetic progression. By identifying the first term and the common difference, the formula for the nth term of an arithmetic progression is used to find the distance covered in the required second.

#Question # 10

This question deals with the population of a town that decreases by a fixed number every year. Such a situation represents an arithmetic progression because the population changes by a constant amount annually. The initial population is taken as the first term, and the yearly decrease is taken as the common difference. Using the formula for the nth term of an arithmetic progression, the population after a given number of years is calculated.

#Question # 11:

In this question, a person climbs a mountain, covering different heights in successive hours. The height climbed each hour increases by a constant amount, forming an arithmetic progression. The height climbed in the first hour and the constant increase are identified as the first term and common difference, respectively. Using the formula for the sum of the first n terms of an arithmetic progression, the total height climbed is equated to the given height to find the total number of hours taken.