Let the number be X Decreasing 2 from XX - 2 = 80 x (1/X)X^2 - 2X = 80X^2 -2x -80 = 0(X-10)(X+8) = 0x=10,-8X has two values, but among the given options X value should be 10
Let the weight of vesel = x kg Then, 1/4 of volume of water = (5.25 - x)kg Full volume of water = (16.5 - x)∴ 4(5.25 - x) = (16.5 - x)⇒ 21 - 4x = 16.5 - x ⇒ 21 - 16.5 = 3x ∴ x = 4.5/3 = 1.5 kg