In maths class, the girl to boys' ratio is 8:6. If there are 24 girls in the class, how many boys are there?

Appeared in: RML Lucknow - 2021

Explanation

The given ratio of girls to boys is 8:6.
The actual number of girls is 24, which is 3 times the ratio value for girls (24 ÷ 8 = 3).
To maintain the same ratio, the number of boys must also be 3 times its ratio value.
Multiplying the ratio value for boys (6) by the factor of 3 gives the actual number of boys: 6 × 3 = 18.

Option A: If there were 20 boys, the ratio of girls to boys would be 24:20. This simplifies to 6:5, which is not the same as the given ratio of 8:6.
Option B: If there were 30 boys, the ratio of girls to boys would be 24:30. This simplifies to 4:5, which is not the same as the given ratio of 8:6.
Option D: If there were 16 boys, the ratio of girls to boys would be 24:16. This simplifies to 3:2. The original ratio 8:6 simplifies to 4:3, so this is incorrect.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Ratio and Proportion as background academic context rather than a clinical decision trigger.
While not a clinical question, this tests basic numeracy and proportional reasoning, which are fundamental skills for nurses.
Nurses use ratio and proportion calculations daily for tasks like medication dosage calculations, IV drip rate adjustments, and interpreting lab results.
For example, if a medication is available as 50 mg in 2 mL, a nurse uses ratios to determine how many mL to administer for a 25 mg dose.

How to Approach the Question

First, identify the core information provided: the ratio of girls to boys (8:6) and the actual number of girls (24).
Recognize that the question asks for the unknown number of boys that corresponds to the given number of girls while maintaining the same ratio.
Set up a proportion. A proportion is an equation stating that two ratios are equal. Let 'x' be the number of boys: 8/6 = 24/x.
Solve for 'x'. You can do this by cross-multiplication (8 * x = 6 * 24) or by finding the scaling factor (24 / 8 = 3) and applying it to the other part of the ratio (6 * 3 = 18).
Select the option that matches your calculated result.

Concept Tested & Keywords

QifbzugohL8ftZkTbvj1rf

Practise the full RML Lucknow - 2021

Attempt every question from this paper in a timed mock, then review the full solution for each one.