A rhombus shaped field has green grass for 18 cows to graze. If each side of the rhombus is 30 m and its longer diagonal is 48 m, how much area of grass field will each cow be getting?

Let the rhombus be denoted by ABCD, where AB = BC = CD = DA = 30 m. Let the longer diagonal be AC = 48 m. Since the diagonals of a rhombus bisect each other at right angles, let the diagonals intersect at point O. Then AO = OC = 48/2 = 24 m. In right-angled triangle AOB, we have AB² = AO² + BO², so BO² = AB² - AO² = 30² - 24² = 900 - 576 = 324. Therefore, BO = √324 = 18 m. The length of the shorter diagonal BD is 2 * BO = 2 * 18 = 36 m. The area of the rhombus is given by (1/2) * d1 * d2, where d1 and d2 are the lengths of the diagonals. Area of the rhombus = (1/2) * 48 * 36 = 24 * 36 = 864 square meters. Since there are 18 cows, the area of grass field each cow will be getting is 864 / 18 = 48 square meters.