Please solve this

Asked by aastharoy997 | 10th Apr, 2020, 10:29: AM

Expert Answer:

In January 2016, Kishan's salary was Rs. 6000. In each of the remaining months of that year his salary was Rs. 500 more than that in the previous month. Find his average monthly salary in that year.
Solution:
Kishan's every month salary for the year 2016 are
6000, 6500, 7000, 7500, .....
This forms an AP with first term a = 6000, common difference d = 500 and total there are total 12 terms.
Sum of the salaries is
S12 = 6[2a+11d]
= 6[2 x 6000 + 11 x 500] = 6[12000 + 5500] = 105,000
Average salary = Total sum/12 = 105000/12 = 8750
Hence, Kishan's average salary is Rs. 8,750.

Answered by Renu Varma | 10th Apr, 2020, 11:07: AM