The average salary in an industry having a staff of 16 engineers and 30 clerks is Rs. 750. The average salary of engineers is Rs. 1200. Find the average salary of clerks.

A 480

B 500

C 510

D 515

E 525

Correct Answer: Option C

∵ The average salary of 16 engineers and 30 clerks is Rs. 750,

750 = Sum of salaries of all people/(16 + 30)

⇒ 750 = Sum of salaries of all people/46

⇒ Sum of salaries of all people = 750 × 46 = 34500

Now, the average salary of engineers is Rs. 1200

∴ 1200 = Sum of salaries of 16 engineers/16

⇒ Sum of salary of all 16 engineers = 1200 × 16 = 19200

∴ Sum of salaries of all clerks = Sum of salaries of all people – Sum of salaries of all engineers

⇒ Sum of salaries of all clerks = 34500 – 19200

⇒ Sum of salaries of all clerks = 15300

Average salary of clerks = Sum of salaries of clerks/Number of clerks

∴ Average salary of clerks = 15300/30

⇒ Average salary of clerks = Rs. 510