(d) Let, number of deers = x and number of ducks = y Total head counted = 180 ∴ x + y = 180 ..........(i) Total legs counted = 448 ∴ 4x + 2y = 448 ⇒ 2x + y = 224 .......(ii) On solving Eqs. (i) and (ii), we get x = 44 and y = 136 ∴ Number of deers = x = 44