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
Sum of the decimal places = 7 .Since the last digit to the extreme right will be zero ( 5 * 4 = 20), so there will be 6 significant digits to the right of the decimal point....