A tank is full of 500 L of water. If the capacity of a bucket is 20 L, how many buckets in all can be filled with the water in 20 tanks?

The correct option is C 500
Capacity of a tank = 500 L
Water filled in 20 tanks = 500 L $\times$ 20
So, in total, there will be 10000 L in 20 tanks.
Capacity of a bucket = 20 L
So, to calculate the number of buckets that can be filled, we need to divide 10000 by 20.

$$\begin{array}{c}500\\ 2010000\\ -\underset{–}{100}2\\ 00\\ -\underset{–}{00}\\ 00\\ -\underset{–}{00}\\ 0\end{array}$$
Thus, a total of 500 buckets can be filled with the water from 20 tanks.