Any multiple of 5 greater than 20 is a possible number of marbles.
There are many, many possible answers to this question.
If there are exactly 20 marbles in the bag, how many of each colour are there?
There will be 8 white and 12 blue marbles, meaning 20 altogether.
Remember that a ratio can be written as a fraction:
We can write the following equivalent fractions:
The possible number of marbles in the bag could be:
(Note that 2+3 = 5)