Question

07. A person is employed in a company for a
salary of Rs 6000 per month. If he gets an
increment of Rs 300 per year on his montly
salary, what will be the total amount he
receives in a period of 30 years?
(a) Rs 43,10,000 (b) Rs 37,26,000
(C) Rs 23,10,000 (d) Rs 52,92,000
​

Answer 1

In the first year his salary will be 6000 * 12 = Rs. 72000

In second year it will be (6000+300) * 12 = Rs. 75600

In third year it will be ( 6000+ 300+ 300) *12 = Rs. 79200

and so on…..

72000, 75600, 79200 ….. forms an Arithmetic Progression with Common Difference = 3600

Substituting the values : a = 72000, n=30 and d= 3600 in the formula for SUM of AP { i.e n/2 ( 2a + (n-1) d) } , you get the sum as Rs. 37, 26,000 which is the required solution.