Quantitative Aptitude

Averages

1,527 Questions
All Basic average and reverse calculation 405 Adding or removing an observation 342 Weighted and combined averages 320 Replacement and correction of a recorded value 233 Ratio shortcut for two-group mixtures 111 Equal-distance average speed 59 Age, score, weight, and spending applications 32 Consecutive terms and arithmetic progressions 25

Averages Questions

Multiple choice

Out of 36 students in a hostel, 19 leave. Due to this, the mess expenses come down by \$48 per day, but the average expense per head increases by \$5. What is the new expenditure per day of the mess?
  1. $252
  2. $204
  3. $300
  4. $240

  5. Cannot be determined
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let original average be x and total students be 36. Total expense = 36x. After 19 leave, 17 remain. New total expense = 36x - 48. New average = (36x - 48) / 17. Given (36x - 48) / 17 = x + 5. Solving for x: 36x - 48 = 17x + 85 => 19x = 133 => x = 7. New expenditure = 36(7) - 48 = 252 - 48 = 204.

Multiple choice

The average age of 10 students is 12 years. If the age of a teacher is added to the age of the students, then the average age increases by 1. If the age of another teacher, as old as the first teacher, is included, then what will be the average age of all the 10 students and 2 teachers together (in years)?

  1. 13

  2. 14

  3. 14.83

  4. 13.83

  5. 15
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sum of 10 students = 120. Teacher 1 added: (120 + T) / 11 = 13. 120 + T = 143, T = 23. Two teachers added: (120 + 23 + 23) / 12 = 166 / 12 = 13.833.

Multiple choice

Directions: The following problem consists of a question and two statements marked A and B given below it. You have to decide whether the data provided in the statements is sufficient to answer the question. Read both the statements and give answer accordingly. What is the average of 5 numbers? (A) The sum of 3 numbers is 22. (B) The sum of 2 numbers is 13.

  1. The question can be solved using any one of the statements.

  2. The question can be solved using either of the statements.

  3. The question can be solved using both the statements together but not either alone.

  4. The question cannot be solved using the given statements.
Reveal answer Fill a bubble to check yourself
D Correct answer