IEMCET BBA/BCA aptitude preparation: Compound growth — error clinic and diagnostic check

The error pattern

Applying a yearly rate to a count of months without converting the period mismatches the model.

An error clinic starts with the reason an approach fails, rather than memorising an exception in isolation. State the hidden assumption or changed definition that makes the mistaken approach tempting.

Rebuild the correct model

Compounding applies growth to the accumulated amount, so later increases use a larger base.

A=P(1+r)ⁿ for a fixed periodic rate and n matching periods.

Translate the wording into a clearly defined task before calculating or selecting an option. In arithmetic, identify the reference base and time period. In English, use the complete sentence or passage and preserve its intended meaning rather than relying on a single keyword.

Diagnostic question

What is the interest earned in that example?

Before solving, write one sentence explaining how the error pattern above could affect this question. Then choose a method that keeps the correct definition, convention or model visible.

Diagnostic answer

1210−1000=210.

Compare the actual reasoning steps, not only the final value or chosen word. A correct final result obtained from inconsistent assumptions is not a dependable method for a different problem.

Verification checklist

Return to the wording and test the proposed answer. Check the base of a percentage, the weights in an average and the units in a rate. For language tasks, verify agreement and context without adding facts the passage never supplies.

Keep an error-log entry with the topic, the failed step, the corrected principle and a later reattempt. Track whether the same failure recurs. The purpose is to improve reasoning on this topic; the log is not a certificate of examination performance.

Official sources and verification

Sources checked on 26 October 2026. A source’s date, programme and campus limit which claims it supports. Official pages may change after review.

1. UEM Kolkata — IEMCET 2026 syllabus and instructions

   Historical course-specific preparation guidance. Some introductory route text conflicts with the central portal.

2. IIT Guwahati — GATE 2026 General Aptitude syllabus

   General transferable aptitude topic reference, not an official detailed IEMCET BBA/BCA blueprint.

Found a discrepancy? Send the page and the official notice for correction.