A daily local train ticket costs Rs 110, while a monthly pass costs Rs 2524.5. If Ram buys the monthly pass and travels on the train for 27 days in a month, what percentage of money does he save compared to buying daily tickets every day?

Introduction / Context:
This problem compares the cost of daily tickets with a monthly pass and asks for the percentage savings. It is a classic cost comparison question that involves calculating total expenditure under two scenarios and then converting the difference into a percentage saving.

Given Data / Assumptions:

• Cost of one daily local train ticket = Rs 110.
• Cost of one monthly pass = Rs 2524.5.
• Number of days Ram travels in the month = 27.
• We assume one ticket per day and that the monthly pass covers unlimited travel for those days.

Concept / Approach:
To find the percentage saving, we follow these steps:

• Compute total cost if Ram buys daily tickets for 27 days.
• Compute cost using the monthly pass.
• Find the difference between these two costs.
• Calculate saving percent = (Saving / Cost with daily tickets) * 100.

This gives the effective benefit of choosing the monthly pass over daily tickets.

Step-by-Step Solution:
Step 1: Total cost with daily tickets = 27 * 110. Step 2: Calculate 27 * 110 = 2970. Step 3: Cost with monthly pass = Rs 2524.5. Step 4: Saving in rupees = 2970 - 2524.5 = 445.5. Step 5: Saving percent = (445.5 / 2970) * 100. Step 6: Compute 445.5 / 2970 = 0.15. Step 7: Multiply by 100 to get 0.15 * 100 = 15 percent.

Verification / Alternative check:
We can also compare average cost per day. With daily tickets: 2970 / 27 = Rs 110 per day. With the monthly pass: 2524.5 / 27 = Rs 93.5 per day. Saving per day = 110 - 93.5 = Rs 16.5. Ratio = 16.5 / 110 = 0.15, which again gives a 15 percent saving. The two methods agree, so the answer is verified.

Why Other Options Are Wrong:
12 percent: Underestimates the saving and does not match the correct fraction 445.5 / 2970. 14 percent: Close but still less than the correct calculated percentage. 18 percent: Overestimates the saving and leads to an incorrect daily cost comparison. 10 percent: This is too low and does not reflect the actual price difference between the two options.

Common Pitfalls:
Students sometimes divide the saving by the monthly pass cost instead of the daily-ticket cost when calculating the percentage saving. Another mistake is miscalculating the number of days of travel or ignoring the fractional part in 2524.5, which changes the final percent. Always ensure you use the correct base value in the percentage formula and do careful arithmetic when decimals are involved.

Final Answer:
Ram saves 15 percent by buying the monthly pass instead of daily tickets for 27 days.