9514 1404 393
Answer:
53
Explanation:
1/3 of the 90 Injas are Werfs, so there are 30 Werfs. Of the remaining 60 Injas that are not Werfs, 8-1 = 7 are Rivads. So, the number of Injas not Werfs or Rivads is 60 -7 = 53.
__
Elaboration on 7
Of the 8 Rivads that are Injas, one of them is a Werf, so was already counted when we counted 30 Werfs. The other 7 are Injas that are Rivads, but not Werfs.