Given that, the total no. of seats available were 49,000.Seats for General category were 28,200,for SC were 7,400 and for ST were 3,700.
The percentage of seats available for students of SC and ST taken together -

⇒ seats for SC and ST together = seats for SC + seats for ST
= 7,400 + 3,700
= 11,100
⇒ The percentage of seats available for students of SC and ST taken together

= 22.65%