Time Equal. Uniform Acceleration. Distance = ???

Classical Mechanics Level 2

A body starts from rest and is uniformly accelerated for a minute. Distance traveled in first 20 seconds is ${ x }_{ 1 },$ in the next 20 seconds is ${ x }_{ 2 },$ and in the last 20 seconds is ${ x }_{ 3 }.$

If ${ x }_{ 1 },$ ${ x }_{ 2 }$ and ${ x }_{ 3 }$ are in the ratio $A:B:C,$ where $A,B,$ and $C$ are coprime positive integers, then what is $A+B+C?$