the value of common attribute (B in this case) should match. but in relation their is no specification of key . so it may be the case that all b in R and S are different . and all values are the same and values may be indistinct bcz b is not key . so maximum will M*N .
Max= 60000 when all value of b in R (a,b,c) matches with all value of b in S (b,d,e).
Min= 0 when none of values matches