Henry has 4 times as much money as David. David has 3 times as much money as Ryan. The total money of the three boys is $128. How much does Henry have?
Start with the smallest amount, usually that avoids fractions ...
Let Ryan's amount be x
then David has 3x , and
Henry has 4(3x) or 12x
now it is easy:
x + 3x + 12x = 128
etc