A bucket holds 30 litre of water. If it has 20 litre 250 ml of water in it, it can hold more.

The correct option is B 9 litre 750 ml
Given:
Capacity of Bucket to hold water = 30 litre
Water in the bucket = 20 litres 250 ml

Space remaing in the bucket = Amount of water bucket can still hold

Amount of water bucket can still hold = 30 litre - 20 litre 250 ml

$\begin{array}{cc}\text{litre}\text{ml}& \\ 30000& \\ \underset{–}{-20250}& \\ 9750& \end{array}$

i.e, Bucket can hold 9 litre 750 ml more water.