Let the number of officers = x
Number of workers = (400 - x)
Average salary of officers = Rs 10,000
Total salary = Rs 10,000x
Average salary of workers = Rs 2,000
Total salary = Rs (400 - x) × 2,000
Total salary of officers and workers = 400 × 3,000
According to the statement,
10,000x + 8,00,000 - 2,000x = 12,00,000
8,000x = 4,00,000
8x = 400
x==50officers