The number of watches sold in Town X in July was 10% more than the number of watches sold in the same town in May. What is the ratio of the number of watches sold in July to that sold in January in the same town?

Answer: Option E

Number of watches sold in Town X in the month of May = 180
Number of watches sold in Town X in the month of July
= $$\frac{180\times 110}{100}$$
= 198
Number of watches sold in Town X in the month of January = 120
∴ Required ratio
$$\begin{array}{rl}& =\frac{198}{120}\\ & =\frac{33}{20}\\ & =33:20\end{array}$$