Database
consider $r1(A,B,C),r2(C,D,E)$ and $r3(F,G)$ with primary key $A,C,F, r1$ has $150 ,r2$ has $100$ and $r3$ has $75$ tuples the number of tuples in $r1$ natural join $r2$ natural join $r3?$
consider $r1(A,B,C),r2(C,D,E)$ and $r3(F,G)$ with primary key $A,C,F, r1$ has $150 ,r2$ has $100$ and $r3$ has $75$ tuples the number of tuples in $r1$ natural join $r2$ ...