Given: –

An initial salary that will be given = ₹26000

There will be an automatic increase of ₹250 per month from the very next month and

thereafter.

Hint: – In the given information the salaries he receives are in A.P.

Let the number of the month is n.

Initial salary = a = ₹26000

Increase in salary = common difference = d = ₹250

i. Salary for the 10th month,

n = 10,

Salary = a + (n – 1)×d

= 26000 + (10 – 1)×250

= 28250

∴ Salary for the 10th month = ₹28250

ii. Total earnings during the first year = sum off all salaries received per month.

Total earnings =

$\frac{n}{2}[2a+(n\u20131\left)d\right]$Here n = 12.

Total earnings=

$\frac{12}{2}[2\times 26000+11\times 250]$= 6×(42000 + 2750)

= 268500

Total earnings during the first year = ₹268500