[tex] \quad \qquad\huge \underline{\boxed{\sf Answer}}[/tex]
Let's assume the ratio constants in terms of x ~
that is ;
and
Now, according to question ~
[tex] \qquad \sf \dashrightarrow \: 2x + 3x = 30[/tex]
[tex]\qquad \sf \dashrightarrow \: 5x = 30[/tex]
[tex]\qquad \sf \dashrightarrow \: x = 30 \div 5[/tex]
[tex]\qquad \sf \dashrightarrow \: x = 6[/tex]
So, Derek gets :
[tex]\qquad \sf \dashrightarrow \: 2x = 2 \times 6 = £12[/tex]
And Eric gets :
[tex]\qquad \sf \dashrightarrow \: 3x = 3 \times 6 =£ 18[/tex]