The starting salary for a particular job is 1.2 million per annum. The salary increases each year by 75000 to a maximum of 1.5million. In which year is the maximum salary reached

In the 5th year

For the first year, the salary is 1.2million = 1,200,000

For the second year, the salary is 1.2million + 75000 = 1,200,000 + 75,000 = 1,275,000

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For the last year, the salary is 1.5million = 1,500,000

This gives the following sequence...

1,200,000 1,275,000  .   .   . 1,500,000

This follows an arithmetic progression with an increment of 75,000.

Remember that,

The last term, L, of an arithmetic progression is given by;

L = a + (n - 1)d           ---------------(i)

Where;

a = first term of the sequence

n = number of terms in the sequence (which is the number of years)

d = the common difference or increment of the sequence

From the given sequence,

a = 1,200,000                          [which is the first salary]

d = 75,000                               [which is the increment in salary]

L = 1,500,000                          [which is the maximum salary]

Substitute these values into equation (i) as follows;

1,500,000 = 1,200,00 + (n - 1) 75,000

1,500,000 - 1,200,000 = 75,000(n-1)

300,000 = 75,000(n - 1)

4 = n - 1

n = 5

Therefore, in the 5th year the maximum salary will be reached.