Number System & Average MCQs for Rajasthan SI
Practice 20 free Number System & Average questions under Arithmetic — Maths.
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Rajasthan SI — Arithmetic — Number System & Average
20 Questions • Instant results & explanations • Hindi & English
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Question 1 of 20
The present ages of A and B are in the ratio 3:4. After 5 years, this ratio becomes 4:5. What is the present age of A?
Question 2 of 20
The average age of a class of 30 students is 15 years. If the teacher's age is included, the average becomes 16 years. What is the teacher's age?
Question 3 of 20
The average of 10 numbers is 30. If one number 15 is incorrectly read and replaced by 45, what will be the new average?
Question 4 of 20
The average age of A and B is 20 years, B and C is 19 years, and A and C is 21 years. What is the age of A?
Question 5 of 20
What is the unit digit in the product (3^65 × 6^59 × 7^71)?
Question 6 of 20
If the expression [(8 - 5) ÷ {(4 - 2) + (2 + 8/13)}] is mathematically modified by removing the fraction 8/13 entirely from the equation, what will be the new resulting value?
Question 7 of 20
The mean of 100 observations was calculated as 49. It was later discovered that three observations taken as 40, 20, 50 were actually 60, 70, 80 respectively. What is the correct mean?
Question 8 of 20
What is the value of √(6 + √(6 + √(6 + ... ∞)))?
Question 9 of 20
A batsman makes a score of 87 runs in the 17th inning, and thus increases his average by 3. Find his average after the 17th inning.
Question 10 of 20
The average age of a class of 30 boys is 15 years. If the teacher's age is included, the average age increases by 1 year. What is the age of the teacher?
Question 11 of 20
The average of 10 numbers is 15. If each number is multiplied by 3, what will be the new average?
Question 12 of 20
What is the smallest prime number?
Question 13 of 20
The average age of 8 men increases by 2 years when a new person replaces a 20-year-old man. What is the age of the new person?
Question 14 of 20
A batsman in his 10th innings makes a score of 80 runs, and thereby increases his average by 2 runs. What was his average after the 10th innings?
Question 15 of 20
A batsman in his 12th innings makes a score of 63 runs and thereby increases his average by 2. What is his average after the 12th innings?
Question 16 of 20
The average of 50 numbers is 36. It was later found that a number 48 was wrongly read as 23. Find the correct average.
Question 17 of 20
The average age of 30 boys is 14 years. When the teacher is included, the average becomes 15 years. What is the teacher's age?
Question 18 of 20
The average of 50 numbers is calculated as 40. Later it was found that one number 45 was wrongly read as 20. What is the correct average?
Question 19 of 20
The average age of 10 persons increases by 2 years when a person aged 25 years is replaced by a new person. What is the age of the new person?
Question 20 of 20