Question

Tanvy joined her job in a company in the year 2015 on a monthly salary of Rs. 40000 with an annual increment of Rs. 2500. In which year will she get Rs. 65000 as monthly salary?

Answer 1

Monthly salary received by Tanvy in 2015, 2016, 2017, 2018,… is respectively Rs. 40000, Rs. 42500, Rs. 45000, Rs. 47500, ….
This is an AP with a = 40000, d = 2500 and l = 65000.
Let the number of terms of this AP be n. Then,
`T_(n) = 65000 rArr a + (n-1) d = 65000`
`rArr 40000 + (n-1) xx 2500 = 65000`
`rArr (n-1) xx 2500 = 65000 - 40000 = 25000`
`rArr (n-1) = (25000)/(2500) = 10 rArr n = 11.`
Thus, the 11th annual salary received by Tanvy will be Rs. 65000. Thus, after 10 years, i.e., in the year 2025, her annual salary will be Rs. 65000.