AFCAT I 2018 Solved Paper

Let total number of workers be n
total salary of all workers = 8000 n
total salary of 7 technicians = 7 × 12000 = 84,000
total salary of remaining workers = (n - 7) × 6000
84000 + (n - 7) × 6000 = 8000 n
84 + 6n – 42 = 8n
42 = 2n
n = 21