Respuesta :

The answer to this is 28:3
Add up 3 and 1:  3+1 = 4.  The corresponding fractions are 3/4 and 1/4.

(3/4)(28) =21
(1/4)(28)  = 7

Then 21 and 7 add up to 28, as required, and are in the ratio 3:1.