Problem Solving

Hi I read somewhere that one can calculate the LCM and HCF of fractions using the below mentioned principle -

LCM OF a/b and c/d =
LCM OF Numerators (a and c)/ HCF of denominators (b and d)

Similarily,

HCF of a/b and c/d =

HCF of Numerators(a and c)/ LCM of denominators (b and d)

Is this correct or is there any other approach?

Coz,

if i find the LCM of 5/3 and 7/11 by this rule I get it = 35 which is plain wrong as 35 is not a multiple of 5/3 and 7/11

Experts, pls tell me if we can calculate the LCM and HCF of fractions

Thanks

Those formulae are correct. Also, the answer to your example is correct. You should not be checking the result against the fraction, as only the numerators of both fractions are multiples of 35. The denominator is the HCF of those fractions

Yes, but then how can 35 be a multiple of 5/3?? Doesn't it defy the LCM principle?

No it does not... The formulae are correct. 35 is indeed a multiple of 5/3. To find the factor divide 35/(5/3). You get 21. conversely, multiply 21 by 5/3.. 5/3*21 = 35. Similarly, 35/(7/11) gives 55. Conversely, 55*7/11= 35.

Hope this helps.

zaarathelab wrote:Yes, but then how can 35 be a multiple of 5/3?? Doesn't it defy the LCM principle?