A body weighs W1 in a liquid of density d1 and W2 in a liquid of density d2. What is the weight in a liquid of density d3?
W3 = W2(d3−d1)−W1(d3−d2)d2−d1
W1 = mg [1−d1D] = W[1−d1D] .........(a)
Similarly, W2 = mg [1−d2D] = W[1−d2D] .........(b)
and W3 = mg [1−d3D] = W[1−d3D] .........(c)
Using (a) , (b) & (c) we obtain
W3 = W2(d3−d1)−W1(d3−d2)d2−d1