Muft Shiksha™ एक 100% Free Education Portal है 🇮🇳, जिसका उद्देश्य Class 9–12 के हर विद्यार्थी तक High-Quality Education को पूरी तरह मुफ्त पहुँचाना है। 🇮🇳 हम मानते हैं कि अच्छी शिक्षा किसी student की आर्थिक स्थिति पर निर्भर नहीं होनी चाहिए। 🇮🇳 हर विद्यार्थी को वही Quality Study Material, MCQs, Quizzes, Exam Preparation, Concept-Based Learning और Bilingual Support मिलना चाहिए, जो आमतौर पर महंगी Coaching या Premium Platforms में मिलता है। Muft Shiksha™ 🇮🇳 इसी सोच के साथ बनाया गया है
In this Class 10 Mathematics topic from the chapter Real Numbers, students learn that every integer greater than 1 can be expressed as a product of prime numbers, and that this prime factorisation is unique apart from the order of the factors. They practise finding prime factors and use the theorem to understand and determine the HCF and LCM of numbers. The topic builds clear reasoning about the structure of whole numbers and supports later work with divisibility and number relationships.
TOPIC PRACTICE
Quiz this set
Up to 20 questions from this page. Select your focus, then start.
If a number has prime factorisation (2^{12}\times3^9\times5^4\times7^3\times17), how many distinct prime factors does it have?
Correct answer: A
Step 1: When counting distinct prime factors, exponents are not added. Step 2: The prime bases are 2, 3, 5, 7, and 17. Step 3: Therefore, the number of distinct prime factors is 5.
If the two numbers are (2^9\times3^5\times13) and (5^6\times7^4\times11), which statement about them is correct?
Correct answer: A
Step 1: The prime factors of the first number are 2, 3, and 13. Step 2: The prime factors of the second number are 5, 7, and 11. Step 3: There is no common prime factor, so they are co-prime.
Step 1: Recognise (2822400=1680^2). Step 2: Since (1680=2^4\times3\times5\times7), (1680^2=2^8\times3^2\times5^2\times7^2). Step 3: In a perfect square, all prime exponents are even.
If (n=2^8\times3^7\times5^4\times23), by which number must (n) be divisible?
Correct answer: A
Step 1: (502929=3^7\times23). Step 2: Both prime factors are present in (n) with sufficient powers. Step 3: Therefore, (n) must be divisible by 502929.
If (n=2^{10}\times3^6\times5^4), by which of the following will (n) not be divisible?
Correct answer: D
Step 1: In (n), the powers are (2^{10}), (3^6), and (5^4). Step 2: (28125=3^2\times5^5), which needs power 5 of 5. Step 3: Since (n) has only (5^4), (n) is not divisible by 28125.
If a number has prime factorisation (2^{12}\times3^8\times5^5), what is the smallest number by which it must be multiplied to make a perfect cube?
Correct answer: A
Step 1: For a perfect cube, exponents must be multiples of 3. Step 2: (2^{12}) is already suitable, while (3^8) and (5^5) must become (3^9) and (5^6). Step 3: The smallest multiplier is (3\times5).
By which smallest number should 254016 be divided to get a perfect square?
Correct answer: A
Step 1: (254016=2^6\times3^4\times7^2). Step 2: All powers are even, so the number is already a perfect square. Step 3: If it is already a perfect square, the smallest divisor is 1.
If (x=2^8\times3^5\times7^6) and (y=2^6\times5^4\times7^7), what will be the power of 7 in (xy)?
Correct answer: B
Step 1: In multiplication, exponents of the same prime base are added. Step 2: The power of 7 in (x) is 6 and in (y) is 7. Step 3: In (xy), the power of 7 is (6+7=13).
If (x=2^{10}\times3^6\times5) and (y=2^9\times3^3\times11^2), what will be the power of 2 in (xy)?
Correct answer: C
Step 1: Powers of the same base 2 are added in multiplication. Step 2: The power of 2 in (x) is 10 and in (y) is 9. Step 3: The total power is (10+9=19).
If (a=2^8\times3^5\times17^2) and (b=2^6\times3^7\times5^2\times17), what is the HCF of (a) and (b)?
Correct answer: A
Step 1: The common prime factors are 2, 3, and 17. Step 2: The smaller powers are (2^6), (3^5), and (17^1). Step 3: (64\times243\times17=264384), so the HCF is 264384.
If (a=2^8\times3^5\times17^2) and (b=2^6\times3^7\times5^2\times17), which is the LCM of (a) and (b)?
Correct answer: A
Step 1: For LCM, take the highest powers of all prime factors. Step 2: The highest powers are (2^8), (3^7), (5^2), and (17^2). Step 3: So the correct form is (2^8\times3^7\times5^2\times17^2).
If the HCF of two numbers is 720 and their LCM is 100800, what is the power of 2 in their product?
Correct answer: C
Step 1: The product is (720\times100800). Step 2: (720=2^4\times3^2\times5) and (100800=2^6\times3^2\times5^2\times7). Step 3: The power of 2 in the product is (4+6=10).
Google Analytics helps us understand site usage. Google may send limited cookie-free signals before your choice. The Live Visitors widget operates independently of this analytics choice; see the privacy policy for its provider and fallback details. Essential site features work without analytics cookies. You can change your choice later in Privacy choices. Privacy policy