Exercise 1.2: Fundamental Theorem of Arithmetic
This exercise is all about breaking numbers into prime factors and using those factors to find HCF and LCM. It's one of the most tested exercises in board exams.
Extra Practice Questions
These questions cover the same concepts as Exercise 1.2. Try solving them to build confidence before or after the textbook exercise.
What is the HCF of 12 and 18?
Find the HCF of 867 and 255 using Euclid's division algorithm.
The LCM of 4 and 6 is:
0.235235235... is a:
The LCM of 15 and 20 is:
Show that the product of three consecutive positive integers is divisible by 6. What property is used?
Which of the following is an irrational number?
Without actually dividing, determine which of these will have a terminating decimal: 13/3125
Find the HCF of 1848, 3058, and 1331 using Euclid's algorithm step by step. What is the first step?
Find the largest number that divides 2053 and 967 and leaves remainders 5 and 7 respectively.
Stuck on a question?
Paste any question from Exercise 1.2 into our AI Maths Solver and get a step-by-step solution instantly. It works for all NCERT questions.
Try AI Solver — FreeCommon Mistakes to Avoid
- ✗Missing a prime factor during factorisation
- ✗Confusing HCF (take lowest powers) with LCM (take highest powers)
- ✗Forgetting to verify that HCF × LCM = product of the two numbers
- ✗Not simplifying the factor tree completely
Other Exercises in Chapter 1
Frequently Asked Questions
How many questions are in NCERT Class 10 Exercise 1.2?
Exercise 1.2 has 7 questions covering prime factorisation, HCF, and LCM using the Fundamental Theorem of Arithmetic.
What is the Fundamental Theorem of Arithmetic?
Every composite number can be expressed as a product of primes in a unique way (apart from the order of factors). For example, 12 = 2 × 2 × 3.
How do you find HCF and LCM using prime factorisation?
For HCF, take the lowest power of each common prime factor. For LCM, take the highest power of every prime factor that appears in either number.
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