If `A + A = 30, B + B = 20 and C + C = 8` . Then `A + B xx C = ` ?

If A = {a,b,c} , B={b,c,d} and C = {a,d,c}, then (A-B)xx (B nnC)=

If a + b + c = 0 , then find the value of ( ( a + b ) / c + ( b + c )/a + ( c + a ) / b ) times ( a /( b + c ) + b /( c + a ) + c /( a + b ) ) is :

If A= [a,b,c], B= [c,d] and C= [d,e,f] , Find (i) A xx (B uu C) (ii) (A nn B) xx C (iii) (A xx B) nn (B xx C)

If A = [1,2,3], B=[4], C= [5] , then verify that: (i) A xx (B uu C) = (A xx B) uu (A xx C) (ii) A xx (B nn C) = (A xx B) nn (A xx C)