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
अभाज्य गुणनखंडन द्वारा महत्तम समापवर्तक और लघुत्तम समापवर्त्य
In this Class 10 Mathematics topic from Real Numbers, students learn to find the HCF and LCM of two or more numbers through prime factorisation. They break each number into prime factors, compare the resulting powers, and select the appropriate common factors: the lowest powers for HCF and the highest powers for LCM. The topic also develops accuracy in writing factor trees, simplifies comparison between methods, and helps students apply these concepts to numerical and everyday problem-solving situations.
TOPIC PRACTICE
Quiz this set
Up to 25 questions from this page. Select your focus, then start.
25 questions
Choose questions
Hard · Level 7View options
(2)
(3)
(5)
(7)
Hard · Level 7View options
(792)
(720)
(864)
(912)
Hard · Level 7View options
(980)
(840)
(1120)
(560)
Hard · Level 7View options
(2^3\times3\times7)
(2^5\times3^2\times7^2)
(2^3\times3^2\times7^2)
(2^5\times3\times7)
Hard · Level 7View options
(2^7\times3^4\times5\times11)
(2^5\times3^2)
(2^5\times3^4)
(2^7\times3^2)
Hard · Level 7View options
(9702)
(4851)
(6930)
(1386)
Hard · Level 7View options
(864)
(900)
(924)
(972)
Hard · Level 7View options
(192)
(288)
(336)
(360)
Hard · Level 7View options
(540)
(720)
(900)
(1080)
Hard · Level 7View options
(25)
(75)
(125)
(150)
Hard · Level 7View options
(2^2\times3^3\times5)
(2^6\times3^7\times5\times13^2)
(2^2\times3^3\times5\times13)
(2^4\times3^5\times5)
Hard · Level 7View options
(120)
(160)
(240)
(480)
Hard · Level 7View options
(a=5), (b=3)
(a=4), (b=3)
(a=7), (b=2)
(a=6), (b=4)
Hard · Level 7View options
(a=2), (b=1)
(a=4), (b=3)
(a=5), (b=2)
(a=3), (b=4)
Hard · Level 7View options
(177)
(345)
(513)
(681)
Hard · Level 7View options
(42)
(56)
(84)
(126)
Hard · Level 7View options
(1)
(23)
(29)
(667)
Hard · Level 7View options
(704)
(616)
(792)
(880)
Hard · Level 7View options
(2)
(3)
(5)
(7)
Hard · Level 7View options
(45)
(50)
(55)
(60)
Hard · Level 7View options
Their HCF is (22)
Their HCF is (44)
Their LCM is (924)
The two numbers are coprime
Hard · Level 7View options
(4)
(5)
(6)
(10)
Hard · Level 7View options
(2)
(3)
(4)
(5)
Hard · Level 7View options
Such whole numbers are possible
Such whole numbers are not possible
The two numbers must be equal
The two numbers will be coprime
Hard · Level 7View options
(8) metres
(16) metres
(32) metres
(64) metres
Question 1HardLevel 7
If the LCM of (2^a\times3^2\times5) and (2^3\times3^4\times5^2) is (2^5\times3^4\times5^2), which value of (a) is possible?
Correct answer: C
Step 1: The highest power of (2) in the LCM must be (5). Step 2: The second number has power (3), so (a=5) gives the highest power (5). Step 3: For LCM, check the maximum-power condition.
If the HCF of (140) and (196) is (28), what will be their LCM?
Correct answer: A
Step 1: Product of two numbers equals HCF times LCM. Step 2: LCM (=\frac{140\times196}{28}=980). Step 3: Divide (196) by (28) first to get (7), then multiply (140\times7).
Which option correctly gives the HCF of (2^3\times3^2\times7) and (2^5\times3\times7^2)?
Correct answer: A
Step 1: HCF takes the smaller power of each common prime. Step 2: The smaller powers of (2), (3), and (7) are (3), (1), and (1), so HCF (=2^3\times3\times7). Step 3: Match each smaller power with the correct base.
If the prime factorisations of two numbers are (2^7\times3^2\times11) and (2^5\times3^4\times5), what will be their HCF?
Correct answer: B
Step 1: HCF contains only the common prime factors. Step 2: The common primes are (2) and (3), with smaller powers (2^5) and (3^2). Step 3: For HCF, always take the smaller powers.
Step 1: Prime factorise: (63=3^2\times7), (98=2\times7^2), and (154=2\times7\times11). Step 2: The highest powers are (2), (3^2), (7^2), and (11), so the LCM is (9702). Step 3: Include a prime even if it appears in only one number.
The product of two numbers is (66528) and their HCF is (72). What will be their LCM?
Correct answer: C
Step 1: For two numbers, product (=) HCF (\times) LCM. Step 2: LCM (=\frac{66528}{72}=924). Step 3: For large numbers, simplify the division in small steps.
The HCF of two numbers is (48), their LCM is (1440), and one number is (240). What is the other number?
Correct answer: B
Step 1: Product of two numbers equals HCF times LCM. Step 2: The other number is (\frac{48\times1440}{240}=288). Step 3: First simplify (1440) by (240) to make the calculation easier.
What is the smallest number exactly divisible by (54), (72), and (90)?
Correct answer: D
Step 1: The smallest number exactly divisible by all given numbers is their LCM. Step 2: (54=2\times3^3), (72=2^3\times3^2), and (90=2\times3^2\times5), so LCM (=2^3\times3^3\times5=1080). Step 3: Choose the highest powers carefully.
What is the greatest number that can exactly divide (225), (375), and (525)?
Correct answer: B
Step 1: The greatest common divisor is the HCF. Step 2: (225=3^2\times5^2), (375=3\times5^3), and (525=3\times5^2\times7), so HCF (=3\times5^2=75). Step 3: Use only the smallest powers common to all numbers.
If (a=2^4\times3^2\times13) and (b=2^2\times3^5\times5\times13), what is (\frac{\text{LCM}}{\text{HCF}})?
Correct answer: A
Step 1: HCF is (2^2\times3^2\times13), and LCM is (2^4\times3^5\times5\times13). Step 2: On division, subtract the powers of the same bases, giving (2^2\times3^3\times5). Step 3: In prime-power division, subtract exponents.
Three machines give signals at intervals of (16), (24), and (40) minutes respectively. If they signal together now, after how many minutes will they signal together again?
Correct answer: C
Step 1: The next common signal time is the LCM of the intervals. Step 2: (16=2^4), (24=2^3\times3), and (40=2^3\times5), so LCM (=2^4\times3\times5=240). Step 3: For repeated-time questions, use LCM.
If (x=2^a\times3^4\times5) and (y=2^6\times3^b\times11) have HCF (2^5\times3^3), which values are possible?
Correct answer: A
Step 1: HCF uses the smaller power of each common prime. Step 2: The smaller power of (2) must be (5), so (a=5) is possible; the smaller power of (3) must be (3), so (b=3) is possible. Step 3: Check unknown powers separately.
If (m=2^3\times3^a\times7) and (n=2^5\times3^2\times5^2\times7^b) have LCM (2^5\times3^4\times5^2\times7^3), which values are correct?
Correct answer: B
Step 1: LCM contains the highest power of each prime. Step 2: The highest power of (3) must be (4), so (a=4); the highest power of (7) must be (3), so (b=3). Step 3: For LCM, focus on the maximum-power condition.
What is the smallest number that leaves remainder (9) when divided by (28), (42), and (56)?
Correct answer: A
Step 1: Subtracting (9) makes the number divisible by (28), (42), and (56). Step 2: (28=2^2\times7), (42=2\times3\times7), and (56=2^3\times7), so LCM (=2^3\times3\times7=168). Hence the number is (168+9=177). Step 3: Add the common remainder at the end.
A library has (168) mathematics books and (252) science books. They are to be kept in the maximum number of identical boxes so that each box has the same number of both types of books. How many boxes can be made?
Correct answer: C
Step 1: The maximum number of identical boxes is found using HCF. Step 2: (168=2^3\times3\times7) and (252=2^2\times3^2\times7), so HCF (=2^2\times3\times7=84). Step 3: For maximum equal distribution, use HCF.
If (176=2^4\times11) and (264=2^3\times3\times11), what is the sum of their HCF and LCM?
Correct answer: B
Step 1: HCF (=2^3\times11=88). Step 2: LCM (=2^4\times3\times11=528), so the sum is (88+528=616). Step 3: When sum is asked, find both values separately.
If a number is divisible by both (2^5\times3^2\times7) and (2^3\times3^5\times11), what will be the power of (3) in the smallest such number?
Correct answer: C
Step 1: The smallest such number is the LCM of the two given numbers. Step 2: The powers of (3) are (2) and (5), so the higher power (5) will be used. Step 3: For divisibility, choose the higher power.
Step 1: (132=2^2\times3\times11) and (308=2^2\times7\times11). Step 2: The common smaller powers are (2^2) and (11), so HCF (=44). Step 3: Compare prime factors before choosing the statement.
If (A=2^6\times3\times5^2) and (B=2^4\times3^3\times5), what will be the power of (2) in their LCM?
Correct answer: C
Step 1: LCM takes the higher power of a common prime. Step 2: The powers of (2) are (6) and (4), so the higher power is (6). Step 3: In LCM, powers are not added; only the higher power is taken.
If the LCM of (66), (88), and (121) is found, how many distinct prime factors will it have?
Correct answer: C
Step 1: Check prime factors: (66=2\times3\times11), (88=2^3\times11), and (121=11^2). Step 2: The distinct primes in the LCM are (2), (3), and (11), so the count is (3). Step 3: Do not count powers as separate primes.
If the HCF of two numbers is (45) and their LCM is (1260), what is correct about their existence?
Correct answer: B
Step 1: The HCF must exactly divide the LCM. Step 2: (1260) is not exactly divisible by (45), so such whole numbers are not possible. Step 3: Check this necessary condition before searching for pairs.
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