An average age of A, B and C is 45. If the averageage of A and B be 40 and that of B and C be 43, then the weight of B is	Options:  A) 25  B) 29  C) 31  D) 35  E) 36
Let A, B, C represent their respective age's. Then, we have:   A + B + C = (45 x 3) = 135 .... (i)   A + B = (40 x 2) = 80 .... (ii)   B + C = (43 x 2) = 86 ....(iii)   Adding (ii) and (iii), we get: A + 2B + C = 166 .... (iv)   Subtracting (i) from (iv), we get : B = 31.   B's age= 31   31
<result>C</result>
An average age of A, B and C is 45. If the averageage of A and B be 40 and that of B and C be 43, then the weight of B is