Answer:
1 : 3
Explanation:
¼ of the biscuits are chocolate while the rest are plain.
Since a fraction is a part of a whole, 1, then it means that the fraction that are plain is:
1 - ¼ = ¾
Therefore, the ratio of chocolate biscuits to plain biscuits is:
¼ : ¾
To put this in simplest dorm, multiply both sides by 4, we have:
1 : 3
This is the ratio of chocolate biscuits to plain biscuits.