alleryStart learning →Find the average of $5, 10, 15, 20$ and $25$.
- $12$
- $14$
- $15$
- $17$
Show answer and solution
Correct answer: C. $15$
Sum $= 5+10+15+20+25 = 75$.
Average $= \dfrac{75}{5} = 15$.
IIFT Averages — practice questions
Explore 47 free Averages questions in IIFT Quantitative Aptitude. Open each question or exercise to read its content, reference answers and available explanation.
Practise Averages with Quill →Averages questions and exercises with answers
Showing questions 1–30 of 47.
Find the average of $5, 10, 15, 20$ and $25$.Read the answer and worked solution →What is the average of the first five natural numbers?Read the answer and worked solution →A man covers half of a journey at $40$ km/hr and the other half at $60$ km/hr. Find his average speed for the whole journey.Read the answer and worked solution →The average of $11$ numbers is $50$. If the average of the first six is $49$ and that of the last six is $52$, find the sixth number.Read the answer and worked solution →The average weight of A, B and C is $45$ kg. The average of A and B is $40$ kg, and the average of B and C is $43$ kg. Find B's weight.Read the answer and worked solution →The average of 5 numbers is 24. Their sum is:Read the answer and worked solution →A class has 40 boys averaging 65 marks and 20 girls averaging 80 marks. What is the overall average?Read the answer and worked solution →A car travels 60 km at 30 km/h and returns 60 km at 60 km/h. What is the average speed for the round trip?Read the answer and worked solution →The average of 9 numbers is 50. When the largest number is removed, the average drops to 48. What was the largest?Read the answer and worked solution →The average of 5 marks is 72. Four of the marks are 65, 70, 75 and 80. What is the fifth mark?Read the answer and worked solution →A class of 30 students has average marks 60. A new student joins and the average rises to 61. The new student scored:Read the answer and worked solution →A cricketer's average for the first 10 innings was 35. In his 11th innings he scored 79 runs. His new average is:Read the answer and worked solution →Class A has 25 students averaging 70 marks. Class B has 35 students averaging 60 marks. What is the combined average?Read the answer and worked solution →Averages — true or false?Read the answer and worked solution →Average of 5 consecutive even numbers is 20. The smallest is:Read the answer and worked solution →Average, or spread?Read the answer and worked solution →True or false: what an average tells youRead the answer and worked solution →Order the steps: compute a meanRead the answer and worked solution →Averages and spreadRead the answer and worked solution →Complete the contrastRead the answer and worked solution →True or false: reading an average from a reportRead the answer and worked solution →Assertion and reasonRead the answer and worked solution →Uses every value, or only some?Read the answer and worked solution →Two are true, one is notRead the answer and worked solution →Three of these are wrong. Find the one that holds.Read the answer and worked solution →Flip and pair: statistic with its jobRead the answer and worked solution →Tap every measure of central tendencyRead the answer and worked solution →Spot the one that does not belongRead the answer and worked solution →Averages in a data questionRead the answer and worked solution →Complete the meanRead the answer and worked solution →
Worked practice questions
What is the average of the first five natural numbers?
- $2$
- $2.5$
- $3$
- $3.5$
Show answer and solution
Correct answer: C. $3$
Sum $= 1+2+3+4+5 = 15$.
Average $= \dfrac{15}{5} = 3$.
A man covers half of a journey at $40$ km/hr and the other half at $60$ km/hr. Find his average speed for the whole journey.
- $45$ km/hr
- $48$ km/hr
- $50$ km/hr
- $52$ km/hr
Show answer and solution
Correct answer: B. $48$ km/hr
For equal distances, average speed is the harmonic mean: $\dfrac{2xy}{x+y} = \dfrac{2 \times 40 \times 60}{100} = \dfrac{4800}{100} = 48$ km/hr.
Option C ($50$, the arithmetic mean) applies only when *time* is split equally, not distance.
How to practise
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