In an examination. the highest score and the lowest score differed by 55 and the higher one was 9/4 times the lower one.
What is the lowest score?

Correct option is A

Let the lowest score be x. According to the question, the highest score is$$\frac{9}{4}x$$​. It is also given that the difference between the highest and the lowest scores is 55. Therefore,
$$\frac{9}{4}x - x = 55.$$​
Factor out x:
$$\left(\frac{9}{4} - 1\right) x = 55 \quad \Longrightarrow \quad \frac{9}{4}x - \frac{4}{4}x = \frac{5}{4}x = 55.$$​
Solving for x yields
$$x = \frac{55 \times 4}{5} = 44.$$​