Answer:
Phil has 24 more rocks than Peter
Explanation:
Lets make Peter x
Then Phil = 3x because Phil has 3 times as many rocks as Peter.
If the sum of the rocks they both have is 48, add them together.
3x+x=48
Solve the equation.
4x=48
Divide by 4.
x=12
Peter has 12 rocks, Phil has 36 rocks
36-12=24