LIC AAO — Mains — 2019 — Previous Year Paper — Kerala PSC PYQ Practice with Answers

Correct answer (Option E):\nFor Institute A:\nPercentage of girls = 100% - 60% = 40%\nTotal students in A = (80 / 40) × 100 = 200\nNumber of mentors in A = 200 / 8 = 25\n\nFor Institute D:\nPercentage of girls = 100% - 70% = 30%\nTotal students in D = (108 / 30) × 100 = 360\nNumber of mentors in D = 360 / 24 = 15\n\nRequired Percentage:\nPercentage change = ((25 - 15) / 25) × 100 = (10 / 25) × 100 = 40%\nThus, it is 40% less. Option E is correct.\n\nWhy others are wrong:\nOptions A, B, C, and D do not match the calculated value of 40% less.\n\nStudy tip:\nAlways compute the total number of students first by using the percentage of girls (100% - percentage of boys) before dividing by the number of students per mentor.

Correct answer (Option C):\nInitial state of Institute E:\nGirls = 90\nBoys percentage = 64%, so Girls percentage = 36%\nTotal initial students = (90 / 36) × 100 = 250\nInitial Boys = 250 - 90 = 160\nInitial mentors = 250 / 25 = 10\n\nNew state after increments:\nNew Girls = 90 × 1.6 = 144\nNew Boys = 160 × 1.35 = 216\nTotal new students = 144 + 216 = 360\nNew student-to-mentor ratio = 25 × 1.2 = 30\nNew number of mentors required = 360 / 30 = 12\n\nMore mentors required = 12 - 10 = 2. Option C is correct.\n\nWhy others are wrong:\nOptions A, B, D, and E represent wrong differences between old and new counts.\n\nStudy tip:\nEnsure you apply percentage increases directly to the absolute counts of boys and girls respectively, rather than adding to the percentages.

Correct answer (Option D):\nTotal students in B:\nGirls = 144, Girls% = 32%\nTotal students = (144 / 32) × 100 = 450\n\nTotal students in C:\nGirls = 176, Girls% = 55%\nTotal students = (176 / 55) × 100 = 320\nTotal (B + C) = 450 + 320 = 770\n\nTotal students in D:\nGirls = 108, Girls% = 30%\nTotal students = (108 / 30) × 100 = 360\n\nTotal students in E:\nGirls = 90, Girls% = 36%\nTotal students = (90 / 36) × 100 = 250\nTotal (D + E) = 360 + 250 = 610\n\nDifference = 770 - 610 = 160. Option D is correct.\n\nWhy others are wrong:\nOptions A, B, C, and E are numerically incorrect calculations of the standard student totals difference.\n\nStudy tip:\nKeep fractional percentages organized; for instance, 176 / 0.55 simplifies accurately to 320.

Correct answer (Option B):\nTotal students in C:\nGirls = 176, Girls% = 55%\nTotal students = (176 / 55) × 100 = 320\n\nTotal mentors in C = 320 / 16 = 20\nPercentage of male mentors = 100% - 65% = 35%\nNumber of male mentors = 20 × 0.35 = 7. Option B is correct.\n\nWhy others are wrong:\nOptions A, C, D, and E do not match the result of 35% of 20 mentors.\n\nStudy tip:\nComplementary percentage values (100% - female%) quickly give direct pathways to male metrics.

Correct answer (Option D):\nTotal students in D = (108 / 30) × 100 = 360\nTotal students in F = 360 × 1.15 = 414\n\nStudents under one mentor in B = 15\nStudents under one mentor in F = 15 × 1.20 = 18\n\nNumber of mentors in F = 414 / 18 = 23. Option D is correct.\n\nWhy others are wrong:\nOptions A, B, C, and E are the results of incorrect multipliers or operational errors.\n\nStudy tip:\nEnsure compound changes are calculated sequentially: first derive base statistics of D and B, then evaluate relative figures for F.