Question

the number which when subtracted from each of the terms of the ratio 19:31reducing it to 1:4is

Answer 1

let the reduced number = x
(19-x)/(31-x)=1/4
do the cross multiplication

4(19-x)=31-x
76-4x =31-x
76-31=4x-x
45=3x

3x=45

x=45/3

x=15