The average salaryper head of all the workers in a workshop is Rs.850, if the average salary/head of 7technician is Rs.1000 and the average salary/head of the rest is Rs.780, the totalno.of workers in the work-shop is ?
Pick one:
A) 18
B) 20
C) 22
D) 25
E) 26
Let the total number of workers be y.   So sum of salary for all workers = sum of salary of 7 technician + sum of salary for other y -7 workers.   7 x 1000 + 780(y -7) = 850 y   ⇒ 7000 + 780y - 5460 = 850y   ⇒ 70y = 1540   ∴ y = 22   So total number of workers = 22   22
<result>C</result>
The average salaryper head of all the workers in a workshop is Rs.850, if the average salary/head of 7technician is Rs.1000 and the average salary/head of the rest is Rs.780, the totalno.of workers in the work-shop is ?