5. Practice Question Set A — Basic Level (20 MCQs)

A1. [Basic Average] Find the average of 24, 36, 18, 42, and 30. (a) 28　(b) 30　(c) 32　(d) 34

A2. [Consecutive Natural Numbers] Find the average of the first 50 natural numbers. (a) 24.5　(b) 25　(c) 25.5　(d) 26

A3. [Consecutive Even Numbers] Find the average of the first 30 even natural numbers. (a) 29　(b) 30　(c) 31　(d) 32

A4. [Consecutive Odd Numbers] Find the average of the first 25 odd natural numbers. (a) 23　(b) 24　(c) 25　(d) 26

A5. [Average of Squares] Find the average of the squares of the first 10 natural numbers. (a) 35.5　(b) 36.5　(c) 37.5　(d) 38.5

A6. [Average of Cubes] Find the average of the cubes of the first 9 natural numbers. (a) 205　(b) 215　(c) 225　(d) 235

A7. [Weighted Average] 40 students scored an average of 60 marks and 60 students scored an average of 70 marks. Find the combined average marks. (a) 64　(b) 65　(c) 66　(d) 68

A8. [Average Speed – Equal Distance] A man covers a distance at 40 km/h and returns the same distance at 60 km/h. Find his average speed. (a) 46 km/h　(b) 48 km/h　(c) 50 km/h　(d) 52 km/h

A9. [Average Speed – Equal Time] A car travels for 3 hours at 40 km/h and another 3 hours at 60 km/h. Find its average speed. (a) 48 km/h　(b) 50 km/h　(c) 52 km/h　(d) 55 km/h

A10. [Replacement] The average weight of 10 persons increases by 2 kg when a person weighing 50 kg is replaced by a new person. Find the new person’s weight. (a) 65 kg　(b) 68 kg　(c) 70 kg　(d) 72 kg

A11. [Average Age – Join] The average age of 30 students in a class is 12 years. Including the teacher’s age, the average becomes 12.5 years. Find the teacher’s age. (a) 25.5 years　(b) 26.5 years　(c) 27.5 years　(d) 28.5 years

A12. [Effect of Change in One Value] The average of 5 numbers is 20. One number is increased by 15. Find the new average. (a) 21　(b) 22　(c) 23　(d) 24

A13. [Average Age – Time Shift] The present average age of a husband and wife is 28 years. Find their average age 6 years hence. (a) 32 years　(b) 33 years　(c) 34 years　(d) 36 years

A14. [Deviation Method] Using the deviation method, find the average of 41, 43, 47, 49, and 53. (a) 45.6　(b) 46.0　(c) 46.6　(d) 47.2

A15. [Average of Multiples] Find the average of the first 15 multiples of 8. (a) 60　(b) 62　(c) 64　(d) 66

A16. [Basic Average — Exclusion] The average of 6 numbers is 22. If one number is excluded, the average of the remaining 5 numbers becomes 20. Find the excluded number. (a) 28　(b) 30　(c) 32　(d) 34

A17. [Consecutive Numbers — Not Starting from 1] Find the average of all numbers from 20 to 50 (inclusive). (a) 33　(b) 34　(c) 35　(d) 36

A18. [Weighted Average] A shopkeeper mixes 15 kg of tea at ₹100/kg with 25 kg of tea at ₹140/kg. Find the average price per kg of the mixture. (a) ₹120　(b) ₹125　(c) ₹130　(d) ₹135

A19. [Replacement] The average of 12 numbers is 30. A number is replaced by 54, and the average increases by 2. Find the number that was replaced. (a) 26　(b) 28　(c) 30　(d) 32

A20. [Average Speed – Equal Time] A cyclist rides for 2 hours at 12 km/h and another 2 hours at 18 km/h. Find his average speed. (a) 14 km/h　(b) 15 km/h　(c) 16 km/h　(d) 17 km/h