The average salary per head of all the workers in a company is Rs. 90. The average salary of 12 officers is Rs. 520 and the average salary…

Let the number of workers be x.

The average salary per head of all the workers in a company is Rs. 90.

So, the sum of salary of all the workers in the company = Rs. 90x

The average salary of 12 officers is Rs. 520.

So, the total salary of 12 officers = Rs. (520 × 12) = Rs. 6240

The average salary per head of the rest is Rs. 80.

Number of remaining workers = (x – 12)

Then, total salary of the remaining workers = Rs. [80 × (x – 12)]

We can write, 6240 + [80 × (x - 12)] = 90x

⇒ 6240 + 80x - 960 = 90x

⇒ 90x – 80x = 5280

⇒ 10x = 5280

⇒ x = 5280/10 = 528

∴ The number of total workers in the company is 528.