how do you do reduce ratios in a spreadsheet

[Lucy Locket]

Having found the ratio between 2 numbers I need to express it in its lowest
terms.
Is there a formula for doing this when one number may be odd and the other
even?

 

[Gary''s Student]

Just divide by all common factors. For example if the ratio is:
18/27
then the single common factor is 9. Dividing by 9 yields:
2/3

 

[Teethless mama]

=A1/GCD(A1,B1)&"/"&B1/GCD(A1,B1)