In a bag, there are coins of 25 paise, 50 paise and Rs. 1 in the ratio of 6:7:4. If there is Rs. 90 in total, how many 25 paise coins are there?

Appeared in: DSSSB - 29 August 2019 (Shift-2)

Explanation

The ratio of 25 paise, 50 paise, and Re 1 coins is 6:7:4. We can represent the number of coins as 6x, 7x, and 4x, respectively, where 'x' is a common multiplier.
The total value is calculated by multiplying the number of each coin by its value in rupees: (6x × 0.25) + (7x × 0.50) + (4x × 1.00) = 1.5x + 3.5x + 4x = 9x.
Given the total value is Rs. 90, we set up the equation 9x = 90. Solving for x gives x = 10.
The number of 25 paise coins is 6x. Substituting x = 10, we get 6 × 10 = 60 coins.

Option A: If there were 72 coins of 25 paise, then 6x = 72, which means x = 12. The total value would be 9 * 12 = Rs. 108, which contradicts the given total of Rs. 90.
Option B: If there were 54 coins of 25 paise, then 6x = 54, which means x = 9. The total value would be 9 * 9 = Rs. 81, which contradicts the given total of Rs. 90.
Option D: If there were 66 coins of 25 paise, then 6x = 66, which means x = 11. The total value would be 9 * 11 = Rs. 99, which contradicts the given total of Rs. 90.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Solving ratio and proportion problems involving currency as background academic context rather than a clinical decision trigger.
Ratio and proportion problems are a fundamental part of the quantitative aptitude section in many competitive exams, including those for nursing positions.
This type of question tests the ability to translate a word problem into a mathematical equation and solve it systematically, a skill useful for tasks like medication dosage calculation.
Mastery of these concepts is essential for scoring well in the non-nursing, general aptitude sections of the examination.

How to Approach the Question

First, identify the different items (coin denominations) and the ratio of their quantities (6:7:4).
Represent the number of each item using a variable multiplier (e.g., let the number of coins be 6x, 7x, and 4x).
Convert all monetary values to a single, consistent unit. In this case, converting paise to rupees (Rs. 0.25, Rs. 0.50, Rs. 1.00) is easiest.
Formulate an algebraic equation by summing the values of all items and equating it to the given total value: (6x × 0.25) + (7x × 0.50) + (4x × 1.00) = 90.
Solve the equation to find the value of the variable multiplier 'x'.
Finally, use the value of 'x' to calculate the specific quantity asked in the question, which is the number of 25 paise coins (6x).

Concept Tested & Keywords

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Practise the full DSSSB - 29 August 2019 (Shift-2)

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