Question 316518
Let the two parts be A and B.
1.{{{A+B=100}}}
2.{{{A=3B}}}
Use eq. 2 in eq. 1,
{{{3B+B=100}}}
{{{4B=100}}}
{{{highlight(B=25)}}}
Then from eq. 2,
{{{A=3(25)}}}
{{{highlight( A=75)}}}