Total weight of Q, P and R=45×3=135 kg i.e. P + Q + R = 135 ...(i) Total weight of P and Q =36.5×2=73 kg i.e. P + Q = 73 ...(ii) Total weight of Q and R =52×2=104kg R + Q = 104 ...(iii) From Eqs. (i) and (ii), 73 + R = 135 ∴ R = 135 - 73 = 62 Putting the value of R in Eq. (iii), 62 + Q =104 ∴ Q = 104 - 62 =42 kg