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H.C.F & L.C.M. - Online Quiz
Following quiz provides Multiple Choice Questions (MCQs) related to H.C.F & L.C.M.. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.
Answer : A
Explanation
Q 2 - H.C.F of 3240, 3600 and a third number is 36 and their L.C.M is 24 x 3 5 x 52 x 72?
Answer : B
Explanation
3240 = 23 x 32 x 5; 3600 = 24 x 32 52 H.C.F = 36 = 22 x 32. Since H.C.F is the product of the lowest powers of common factors so the the third number must have 22 x 32 as its factor Since L.C.M is the product of highest powers of common prime factors so the third number must have 35 x 72 as its factor Therefore third number = 22 x 35 x 72
Q 3 - The least number, which when divided by 12,15,20 and 54 leaves in each case a remainder of 8, is?
Answer : B
Explanation
Required number = (L.C.M of 12, 15, 20, 54) + 8 = 540 + 8 = 548.
Q 4 - The product of two numbers is 2028 and their H.C.F is 13. The number of such pairs is?
Answer : A
Explanation
Let the numbers be 13a and 13b. then 13a x 13b = 2028 a x b = 12. Now co-primes with product 12 are (1, 12) and (3, 4). So, the required numbers are (13 x 1, 13 x 12) and (13 x 3, 13 x 4) clearly, there are 2 such pairs.
Q 5 - The H.C.F of two numbers is 23 and the other two factors of their L.C.M are 13 and 14. the larger of the two number is?
Answer : C
Explanation
clearly the numbers are (23 x 13) and (23 x 14) Larger number = (23 x 14) = 322.
Answer : B
Explanation
H.C.F. of given fractions = (H.C.F.of denominators)/(L.C.M.of numerators)=2/105 ( H.C.F.of numerators = 2 L.C.M.of denominators =105)
Answer : B
Explanation
1296=24x34 and 2400=25x3x52 HCF=24x3=48
Q 8 - H.C.F and L.C.M of two 3-digit numbers are 29 and 4147 respectively. What is the sum of the numbers?
Answer : C
Explanation
Let the numbers be 29a and 29 b , where a and b are co-primes. Then, 29 a * 29 b + 29*147 ⇒ ab + (29*4147)/(29*29)= 143 co-primes with product 143 are 11 and 13. ∴ numbers are (29*11, 29* 13) i.e , 319, 377 Their sum = (319+377)= 696
Q 9 - The ratio of two numbers is 15:11. Having their H.C.F as 13 ,numbers are:
Answer : D
Explanation
Let the numbers be 15x and 11x . Then , their H.C.F is x. ∴ x= 13 and so the numbers are (15*13, 11*13) i.e , 195, 143
Q 10 - If the product of two co-primes is 117 then their L.C.F should be
Answer : B
Explanation
H.C.F of co-primes=1 H.C.F * L.C.M = Their product = 117 ∴ 1* L.C.M = 117 ⇒L.C.M = 117