The average salary/head of allthe workers in a workshop is Rs.1200, if the average salary/head of 10 technician is Rs.1400 and the average salary/head of the rest is Rs.900, the total no. of workers in the work-shop is ?	Choose one:
A) 18 B) 17 C) 15 D) 19 E) 21

Rationale: let the total number of workers be y . so sum of salary for all workers = sum of salary of 10 technician + sum of salary for other y - 10 workers . 10 x 1400 + 900 ( y - 10 ) = 1200 y ⇒ 14000 + 900 y - 9000 = 1200 y ⇒ 300 y = 5000 ∴ y = 17 so total number of workers = 17 b
Answer: B