Practice PYQ of Real Numbers Chapter 1 Class 10 Maths with handpicked important questions from previous years question paper with solutions.
Q1:
If two positive integers p and q can be expressed as p = 18 a² b⁴ and q = 20 a³ b², where a and b are prime numbers, then LCM(p, q) is?
CBSE [2024]
Easy
Q2:
In a teachers' workshop, the number of teachers teaching French, Hindi and English are 48, 80 and 144 respectively. Find the minimum number of rooms required if in each room the same number of teachers are seated and all of them are of the same subject.
CBSE [2024]
Medium
Q3:
Three bells toll at intervals of 9, 12 and 15 minutes respectively. If they start tolling together, after what time will they next toll together?
CBSE [2024]
Easy
Q4:
If the product of two co-prime numbers is 553, then their HCF is:
CBSE [2024]
Medium
Q5:
If the prime factorisation of 2520 is 2³ × 3ᵃ × b × 7, then the value of a + 2b is:
CBSE [2024]
Medium
Q6:
Given HCF(2520, 6600) = 40, LCM(2520, 6600) = 252 × k, then the value of k is:
CBSE [2024]
Easy
Q7:
Find the greatest number which divides 85 and 72 leaving remainders 1 and 2 respectively.
CBSE [2023]
Medium
Q8:
If 'p' and 'q' are natural numbers and 'p' is the multiple of 'q', then what is the HCF of 'p' and 'q'?
CBSE [2023]
Medium
Q9:
Three bells ring at intervals of 6, 12 and 18 minutes. If all the three bells rang at 6 a.m, when will they ring together again?
CBSE [2023]
Easy
Q10:
Two numbers are in the ratio 2 : 3 and their LCM is 180. What is the HCF of these numbers?
CBSE [2023]
Medium
Q11:
Teaching Mathematics through activities is a powerful approach that enhances students' understanding and engagement. Keeping this in mind, Ms. Mukta planned a prime game for class 5 students. She announces the number 2 in her class and asked the first student to multiply it by a prime number and then pass it to second student. Second student also multiplied it by a prime number and pass it to third student. In this way by multiplying to a prime number, the last student got 173250.
Now, Mukta asked some questions as give below to the students:
(i) What is the least prime number used by students?
(ii) (a) How many students are in the class?
OR
(b) What is the highest prime number used by students?
(iii) Which prime number has been used maximum times?
CBSE [2023]
Hard
Q12:
Find the smallest number which is divisible by both 644 and 462
CBSE [2025]
Easy
Q13:
Two numbers are in the ratio 4 : 5 and their HCF is 11. Find the LCM of these numbers.
CBSE [2025]
Easy
Q14:
Let \( x \) and \( y \) be two distinct prime numbers and \( p = x^2 y^3 \), \( q = xy^4 \), \( r = x^5 y^2 \). Find the HCF and LCM of \( p, q \) and \( r \). Further check if \( \text{HCF}(p, q, r) \times \text{LCM}(p, q, r) = p \times q \times r \) or not.
CBSE [2025]
Medium
Q15:
If \( x = ab^3 \) and \( y = a^3b \), where \( a \) and \( b \) are prime numbers, then \([ \text{HCF}(x, y) - \text{LCM}(x, y)]\) is equal to:
(a) 1 - a³b³
(b) ab(1 - ab)
(c) ab - a⁴b⁴
(d) ab(1 - ab)(1 + ab)
CBSE [2025]
Medium
Q16:
The sum of the exponents of prime factors in the prime factorisation of 4004 is :
CBSE [2025]
Easy
Q17:
The least number which is a perfect square and is divisible by each of 16, 20 and 50, is :
(A) 1200
(B) 100
(C) 3600
(D) 240
CBSE [2025]
Easy
Q18:
Which of the following is a rational number between \(\sqrt{3}\) and \(\sqrt{5}\)
(A) 1·4142387954012...
(B) 2.32\( 0.\overline{6} \)
(C) π
(D) 1·857142
CBSE [2025]
Easy
Q19:
If \((-1)^n + (-1)^8 = 0\), then n is :
(A) any positive integer
(B) any negative integer
(C) any odd number
(D) any even number
CBSE [2025]
Easy
Q20:
If HCF(98, 28) = m and LCM(98, 28) = n, then the value of n 7m is :
CBSE [2025]
Easy
Q21:
Find the greatest number which divides 281 and 1249, leaving remainder 5 and 7 respectively.
CBSE [2024]
Medium
Q22:
If a = 2² × 3ˣ, b = 2² × 3 × 5, c = 2² × 3 × 7 and LCM(a, b, c) = 3780, then find x.
CBSE [2024]
Easy
Q23:
Can the number (15)ⁿ, n being a natural number, end with the digit 0? Give reasons.
CBSE [2024]
Easy
Q24:
If p² = \(\frac{11}{2}\), then p is a/an:
(a) whole number
(b) integer
(c) rational number
(d) irrational number
CBSE [2023]
Easy
Q25:
Assertion (A) : The perimeter of ABC is a rational number.
Reason (R) : The sum of the squares of two rational numbers is always rational.