A false balance has equal arms. An object weights `W_1` when placed in one pan and `W_2` when placed in the other pan. The true weight `W` of the object is.

Options

A. `sqrt(W_1 W_2)`
B. `sqrt(W_1^2 + W_2^2)`
C. `(W_1 + W_2)/(2)`
D. `(2W_1W_2)/(W_1 + W_2)`

Answer

C

Explanation

( c) Let true weight of the object is `W` and weight of right pan is `x` more than left pan.
Now suppose the object is placed in left pan :
`W = W_1 + x`..(1)
Now if the object is placed in right pan.
`W_2 = W + x` …(2)
from (1) and (2) `W = (W_1 + W_2)/(2)`.