how do you find the greatest common factor of three numbers

Question

i am the greatest common factor of three numbers. thier sum is 36. the largest number is twice the smallest and the middle number is the mean of the other two.

Answer 1

 

let smallest number=x

then greatest number=2x

so their mean =x+2x/2

              =3x/2 

 

atq

 

x+2x+3x/2=36

9x/2=36

x=8

 

so numbers are 8,12,16

 

so highest common factor(hcf)=4

 

Thanks.