The average salary per head of the entire staff of an office including the officers and clerks is Rs.90. The average salary per head of the officers is Rs.600 and that of the clerk is Rs.84. If the number of officers is 12, find the number of clerks in the office?
Answer with explanationAnswer: Option D
Let number of clerk be x.
Average salary of entire staff = Rs. 90
Average salary of per head officer = Rs. 600
Number of head officers = 12
Total salary of 12 officer = 600 * 12 = Rs. 7200
Average salary of clerk = Rs. 84
Total salary of clerk = x * 84
12 + x (90) = 7200 + 84x
1080 + 90x = 7200 + 84x
6x = 6120
x = 1020
Hence, Number of clerks in the office = 1020.