Moderate Problems On HCF

Dear Reader,
Below are four problems based on the HCF of two or three numbers with simple steps.

Question 1

HCF of the numbers 23 x 33 x 112 x 23, 22 x 3 x 72 x 113 x 232 is :
a)33396 b)34523 c)45782 d)23846

Answer : a)33396


HCF of the numbers = the product of the lowest powers of the common factors
The prime factors common to given numbers are 2, 3, 11 and 23.
Here, the common prime factors with the lowest power are 22, 3, 112 and 23
Then the product = 22 x 3 x 112 x 23 = 4 x 3 x 121 x 23 = 33396.
Hence the answer is 33396.

Question 2

HCF of the numbers 234, 390 and 8190 is :

a)234 b)390 c)78 d)117

Answer : c)78


First express the given numbers as the product of prime numbers as follows:
i.e., 234 = 2 x 32 x 13
390 = 2 x 3 x 5 x 13
8190 = 2 x 32 x 5 x 7 x 13
The factors common to the three numbers are 2, 3 and 13
And the product of the common factors = 2 x 3 x 13 = 78

Question 3

Find the H.C.F. of 1.8, 1.05 and 3.15
a)0.15 b)0.18 c)1.8 d)1.05

Answer :a)0.15


Note :" H.C.F. and L.C.M. of Decimal Fractions: In given numbers, make the same number of decimal places by annexing zeros in some numbers, if necessary. Considering these numbers without decimal point, find H.C.F. or L.C.M. as the case may be. Now, in the result, mark off as many decimal places as are there in each of the given number"

Making the same number of decimal places, the given numbers are 1.80, 1.05 and 3.15 .
Without decimal places, these numbers are 180, 105 and 315.
Now, H.C.F. of 180, 105 and 315 is 15.
Then H.C.F. of 1.8, 1.05 and 3.15 is 0.15.
Hence the required answer is 0.15.

Question 4

Reduce 900/1890 to lowest terms.

a)20/42 b)90/189 c)10/21 d)30/63

Answer : c).10/21

We know that "If P/Q is any fraction and X/Y is reduced fraction of P/Q as lowest terms then X = P/M and Y = Q/M where M is the HCF of P and Q"

Now, 900 = 22 x 32 x 52
and 1890 = 2 x 33 x 5 x 7
Then the HCF of 900, 1890 = 2 x 32 x 5 = 90.
And 900/90 = 10, 1890/90 = 21

Then the required answer is 10/21

Score Well In SBI & IBPS, PO & Clerk Exams

Related pages

ibps exam tipssbi bank questions and answersmensuration problemssbi bank clarkibps bank booksgeneral awareness for bank exams with answerssolution of permutation and combination problemsibps clerical bookshow to solve probability sumslist of output devices for computeribps clerk exam bookstypes of crossing of chequerbi openingspreparation for ibps poibps careercomputer questions for ibps clerk examhcf bankcurrent affairs & gkibps po reasoning questionsibps exam preparationallahabad grameen bankname of chennai sea port216 cube rootwhat does omr stand for in computerssbi clerkspermutations and combinations problems and solutionsalligation problems and answersibps bank poibps bank formrule of allegation in mathsantonyms for improvepermutations and combinations solved problemssurds indicesairport names in indiaibps posibps question and answersbi compound interest calculatorantonyms of profuselargest peninsula in the worldcompound interest sums with solutionsairport names in indiaprobability aptitudesyntel current openingsbank po preparation books pdflargest salt water lake in indiadifference between open and crossed chequeupcoming ibps po examgrama bankmultilated chequelist of international airportsprofit and loss math problemsantonyms for stridenthow to write bearer chequeonline tmb bankingsurds and indices questions and answers pdfsebi examsbank clerk exam papersibps po examibps po paperibps poslogical reasoning aptitude questionsaryavart gramin bankgeneral awareness for bank exams with answerspermutation and commutationibps clerical booksantonyms for diatribedifference between order cheque and bearer chequeinternational airport in india listallegation questionscomputer for ibps pohow to solve surds and indices problemsbearer cheque and order chequeaptitude logical reasoning questions and answersrule of allegation in mathsquantitative aptitude books for bank examsmensuration sumsdata sufficiency questions and answersibps careerquadrilateral problemsantonyms for diatribe