Question

The LCM of two number is 28 times their HCF the sum of their LCM and HCF is 1740 if one number is 240 then what is other number

Answer 1

LCM = 28 \times HCF 

i.e. L = 28 H 

∴L + H = 1740 

=> 28H + H = 1740 

=> 29H = 1740 

=> H =174029 = 60 

∴L=28×60=1680 

Now,240×secondnumber=1680×60=>Secondnumber

=168060= 420 

[∵Productoftwono.=LCM×HCF ]

∴Sum of digits = 4 + 2 + 0 =6

Answer 2

let the lcm be x and the hcf be y
given that x=28y

also that x+y=1740
x=28y
so,28y+y=1740
29y=1740
y=60

x=28×60=1680

lcm×hcf=product of both numbers
let the other no. be m
60×1680=240×m
m=1680×60/240=420

hope it helps..