If the weight of a body in air is W₁, in a liquid is W₂ and in water is W₃, then :

1. R.D. of liquid = $\dfrac{\text{W}$2 - \text{W}3}{\text{W}1 - \text{W}3}

2. R.D. of liquid = $\dfrac{\text{W}$1 - \text{W}2}{\text{W}1 - \text{W}3}

3. R.D. of liquid = $\dfrac{\text{W}$2 - \text{W}3}{\text{W}1 + \text{W}3}

4. R.D. of liquid = $\dfrac{\text{W}$1 - \text{W}2}{\text{W}1 + \text{W}3}

R.D. of liquid = $\dfrac{\text{W}$1 - \text{W}2}{\text{W}1 - \text{W}3}

Reason — R.D. of liquid = $\dfrac{\text{Weight of liquid displaced by a body}}{\text{Weight of water displaced by the same body}}$

R.D. of liquid = $\dfrac{\text{Weight of body in air (W)}$1 - \text{Weight of body in liquid (W)}2}{\text{Weight of body in air (W)}1 - \text{Weight of body in water (W)}3}

Thus,

R.D. of liquid = $\dfrac{\text{W}$1 - \text{W}2}{\text{W}1 - \text{W}3}