Hi all, just stuck on this maths does anyone have any advice or know how to go about answering it.

4 Balloons were released from ground level at the same time, each with different volumes of helium within. Ignoring wind resistance, the maxium height were measured in meters (m) as follows

Balloon B reached a height of 5 times that of balloon A

Balloon C reached half the height balloon A did

Balloon D reached a height 45m less then Balloon A.

the total height of all the balloons was 500m

a) assign a constant and variable values to the information

b) model individual formulae for the height reached by balloons B,C and D

c) hence model a formula to find the total height reached by the balloons

d) find the total heights reached by all four balloons individually