1. The problem asks for the ratio of chillies to quiches sold by the restaurant on Wednesday. 2. From the graph description, the number of quiches sold on Wednesday is 20. 3. The number of chillies sold on Wednesday is 12. 4. The ratio of chillies to quiches is given by $$\frac{12}{20}$$. 5. Simplify the fraction by dividing numerator and denominator by their greatest common divisor, which is 4: $$\frac{12 \div 4}{20 \div 4} = \frac{3}{5}$$. 6. Therefore, the simplest form of the ratio of chillies to quiches sold on Wednesday is $3:5$.