Question

A, B and C average is 45, B and C average is 40 then find B = ?​

Answer 1

(A+B+C) / 3 = 45

(A+B+C) = 45 * 3 = 135

( B+C) / 2 = 40

( B+C) = 40 * 2 = 80

A = (A+B+C) - ( B+C) = 135 - 80 = 55

Now I don't think you have enough information to find B