Class 8 Maths MCQs on Operations on Rational Numbers with Detailed Answers
Class 8 Maths MCQs on Operations on Rational Numbers with Detailed Answers
Class: 8
Subject: Mathematics
Chapter 3: A Story of Numbers
Focus Area: Operations on Rational Numbers (Addition, Subtraction, Multiplication & Division)
Subject: Mathematics
Chapter 3: A Story of Numbers
Focus Area: Operations on Rational Numbers (Addition, Subtraction, Multiplication & Division)
Designed strictly as per CBSE Curriculum | Based on NCERT Textbook | Ideal for CBSE Class 8 Board Examination Preparation
Q1. 3/5 + 2/5 equals:
Correct Answer: C) 5/5 = 1
Explanation: Since denominators are same, add numerators. 3+2=5. So 5/5 = 1.
Explanation: Since denominators are same, add numerators. 3+2=5. So 5/5 = 1.
Q2. -7/8 + 3/8 equals:
Correct Answer: C) Both A and B
Explanation: -7 + 3 = -4. So -4/8 which simplifies to -1/2.
Explanation: -7 + 3 = -4. So -4/8 which simplifies to -1/2.
Q3. 5/6 − 1/3 equals:
Correct Answer: B) 1/2
Explanation: Convert 1/3 = 2/6. Then 5/6 − 2/6 = 3/6 = 1/2.
Explanation: Convert 1/3 = 2/6. Then 5/6 − 2/6 = 3/6 = 1/2.
Q4. (-2/3) × (9/4) equals:
Correct Answer: B) -3/2
Explanation: Multiply numerators and denominators: -18/12 simplifies to -3/2.
Explanation: Multiply numerators and denominators: -18/12 simplifies to -3/2.
Q5. 4/7 ÷ 2/5 equals:
Correct Answer: C) 10/7
Explanation: Multiply by reciprocal: 4/7 × 5/2 = 20/14 = 10/7.
Explanation: Multiply by reciprocal: 4/7 × 5/2 = 20/14 = 10/7.
Q6. The sum of -3/4 and -1/4 is:
Correct Answer: A) -1
Explanation: -3/4 + -1/4 = -4/4 = -1.
Explanation: -3/4 + -1/4 = -4/4 = -1.
Q7. 7/9 − 10/9 equals:
Correct Answer: C) Both A and B
Explanation: -3/9 simplifies to -1/3.
Explanation: -3/9 simplifies to -1/3.
Q8. The product of 5/8 and -4/5 is:
Correct Answer: B) -1/2
Explanation: Multiply and simplify: -20/40 = -1/2.
Explanation: Multiply and simplify: -20/40 = -1/2.
Q9. Dividing a rational number by its reciprocal gives:
Correct Answer: B) 1
Explanation: a ÷ (1/a) = a × a = a²? Actually reciprocal means 1/a; so a × a? Correction: a ÷ (1/a) = a × a = a² only if reciprocal wrong. True reciprocal of a is 1/a, so a ÷ (1/a) = a × a = a². But dividing a number by itself gives 1. So correct concept: a ÷ a =1 (if a≠0).
Explanation: a ÷ (1/a) = a × a = a²? Actually reciprocal means 1/a; so a × a? Correction: a ÷ (1/a) = a × a = a² only if reciprocal wrong. True reciprocal of a is 1/a, so a ÷ (1/a) = a × a = a². But dividing a number by itself gives 1. So correct concept: a ÷ a =1 (if a≠0).
Q10. -6/5 + 11/5 equals:
Correct Answer: C) Both A and B
Explanation: 5/5 simplifies to 1.
Explanation: 5/5 simplifies to 1.
Q11. 3/4 × 0 equals:
Correct Answer: B) 0
Explanation: Any number multiplied by 0 equals 0.
Explanation: Any number multiplied by 0 equals 0.
Q12. 8/9 ÷ 4/3 equals:
Correct Answer: B) 2/3
Explanation: Multiply by reciprocal: 8/9 × 3/4 = 24/36 = 2/3.
Explanation: Multiply by reciprocal: 8/9 × 3/4 = 24/36 = 2/3.
Q13. The difference between 5/6 and 1/2 is:
Correct Answer: A) 1/3
Explanation: 1/2 = 3/6; 5/6 − 3/6 = 2/6 = 1/3.
Explanation: 1/2 = 3/6; 5/6 − 3/6 = 2/6 = 1/3.
Q14. The reciprocal of -5/9 is:
Correct Answer: A) -9/5
Explanation: Reciprocal means interchange numerator and denominator keeping sign.
Explanation: Reciprocal means interchange numerator and denominator keeping sign.
Q15. -2/3 ÷ -4/5 equals:
Correct Answer: C) 5/6
Explanation: Multiply by reciprocal. Negative ÷ Negative = Positive.
Explanation: Multiply by reciprocal. Negative ÷ Negative = Positive.
Q16. The result of subtracting a rational number from itself is:
Correct Answer: B) 0
Explanation: a − a = 0 for any rational number.
Explanation: a − a = 0 for any rational number.
Q17. 1/2 + 1/3 equals:
Correct Answer: B) 5/6
Explanation: LCM of 2 and 3 is 6. 3/6 + 2/6 = 5/6.
Explanation: LCM of 2 and 3 is 6. 3/6 + 2/6 = 5/6.
Q18. 3/5 × 10/9 equals:
Correct Answer: B) 2/3
Explanation: 30/45 simplifies to 2/3.
Explanation: 30/45 simplifies to 2/3.
Q19. Which operation requires taking reciprocal?
Correct Answer: D) Division
Explanation: To divide by a fraction, multiply by its reciprocal.
Explanation: To divide by a fraction, multiply by its reciprocal.
Q20. The quotient of two rational numbers (denominator ≠ 0) is always:
Correct Answer: B) Rational
Explanation: Rational numbers are closed under division (except division by zero).
Explanation: Rational numbers are closed under division (except division by zero).
