What is the difference between the total number of male doctor s of hospital  A and B together and total number of female doctors  of hospital C and D together?

Total doctors in hospital ‘A’ = 200   Male doctors in hospital ‘A’ = 200 × (75/100) = 150   Female doctors in hospital ‘A’ = 200 – 150 = 50       Total doctors in hospital ‘B’ = 200/2 = 100   Male doctors in hospital ‘B’ = 100 × (30/100) = 30   Female doctors in hospital ‘B’ = 100 – 30 = 70   Total doctors in hospital ‘C’ = 150 – 70 = 80   Female doctors in hospital ‘C’ = 30   Male doctors in hospital ‘C’ = 80 – 30 = 50   Female doctors in hospital ‘D’ = 120   Total number of doctors in all hospitals = 120 × (100/20) = 600   Total doctors in hospital ‘D’ = (600 - 200 - 100 - 80) = 220 Total number of male doctors in hospital 'D' = 220 - 120 = 100 Total number of male doctors of hospital A and B together = 150 + 30 = 180   Total number of female doctors of hospital C and D together = 30 + 120 = 150   Required difference = 180 - 150 = 30