Question

In a school the periodical examinations are held every month. In a session during April 'X' to March 'X + 1', Rakesh, a student of class IV, section B, appeared for each of the periodical exams. The maximum total marks in each periodical exam is 50. The aggregate marks obtained by him in each periodical exam are given below.

	Year X									Year X+1
Months	April	May	June	July	Aug.	Sept.	Oct.	Nov.	Dec.	Jan.	Feb.	March
Marks	35	37	38	38	41	43	45	45	46	47	48	49

In which periodical exams did Rakesh obtain the highest percentage increase in marks over the previous periodical exams?

• A. May
• B. October
• C. December
• D. September

Hint:

For each option, divide that month's increase over the previous month by the previous month's marks, then compare.

Answer 1

The Correct Option is A

Rather than computing every percentage in full, this method compares the four fractions directly using the fact that a smaller base makes the same numerator count for more.

1. Write the four fractions: May gives $\frac{2}{35}$, September gives $\frac{2}{41}$, October gives $\frac{2}{43}$, December gives $\frac{1}{45}$.
2. Compare the three fractions with numerator 2 first: since $35 < 41 < 43$, and a smaller denominator with the same numerator gives a bigger fraction, $\frac{2}{35} > \frac{2}{41} > \frac{2}{43}$. So May already beats September and October.
3. Compare May with December: December's $\frac{1}{45}$ doubled is $\frac{2}{90}$, which is far smaller than $\frac{2}{35}$ since 90 is much larger than 35. So May beats December too.
4. Conclusion: May's fraction $\frac{2}{35}$ is the largest of all four, so May has the highest percentage increase.

This ranking-by-fraction-size approach confirms May without needing exact decimal percentages. \[ \boxed{May} \]