AVERAGE AND AGES (QUANTITATIVE APTITUDE) EPFO UPSCTotal Questions: 3021. The average of 13 results is 70. The average of first seven is 65 and that of the last seven is 75, the seventh result is :(a) 70(b) 70.5(c) 68(d) 67Correct Answer: (a) 70Solution:22. The average of 9 observations was found to be 35. Later on, it was detected that an observation 81 was misread as 18. The correct average of the observations is(a) 28(b) 42(c) 32(d) 45Correct Answer: (b) 42Solution:23. The average of 5 numbers is 306.4. The average of the first two numbers is 431 and the average of the last two numbers is 214.5. What is the third number?(a) 108(b) 52(c) 321(d) None of theseCorrect Answer: (d) None of theseSolution:24. Kamlesh bought 65 books for ₹ 1,050 from one shop and 50 books for ₹ 1,020 from another. What is the average price he paid per book?(a) ₹ 36.40 (b) ₹ 18.20(c) ₹ 24 (d) ₹ 18Correct Answer: (d) ₹ 18Solution:25. The total marks obtained by a student in Physics, Chemistry and Mathematics together is 120 more than the marks obtained by him in Chemistry. What are the average marks obtained by him in Physics and Mathematics together?(a) 60(b) 120(c) 40(d) Cannot be determinedCorrect Answer: (a) 60Solution:26. The average age of 80 boys in a class is 15 years. The average age of a group of 15 boys in the class is 16 years and the average age of another 25 boys in the class is 14 years. What is the average age of the remaining boys in the class?(a) 15.25 years(b) 14 years(c) 14.75 years(d) Cannot be determinedCorrect Answer: (a) 15.25 yearsSolution:27. The average marks in English subject of a class of 24 students is 56. If the marks of three students were misread as 44, 45 and 61 of the actual marks 48, 59 and 67 respectively, then what would be the correct average?(a) 56(b) 55(c) 57.5(d) None of theseCorrect Answer: (d) None of theseSolution:28. The sum of the present ages of P and Q is 25 years more than the age of R. The present age of Q is 5 years more than that of R. Find the present age of P.(a) 20 years(b) 25 years(c) 21 years(d) 22 yearsCorrect Answer: (a) 20 yearsSolution:29. The average of four consecutive even numbers P, Q, R and S respectively (in increasing order) is 51. What is the product of P and R?(a) 2592(b) 2400(c) 2600(d) None of theseCorrect Answer: (d) None of theseSolution:30. The average height of 27 persons was recorded as 162 cm. If the height of Shreya was deleted from the observation, the average height reduced by 1 cm. What was Shreya's height?(a) 184 cm.(b) 226 cm.(c) 179 cm.(d) None of theseCorrect Answer: (d) None of theseSolution:Height of Shreyas = 162 + 26 = 188 cmSubmit Quiz« Previous123