Divide an amount into two unequally

[MrOllyR]

Can anyone help with this?

I have transport costs of $1000 (or whatever the amount is in cell A1) and this needs to be split between two different groups of people.
In group A (cell A2) there are 2 people.
In group B (cell A3) there are 5 people.

I need to be able to share the total cost of $1000 between group A and B.
Do you have a formula to workout how much each group should pay based on the number of people in each group? i.e. if group A had 1 person and group B had nobody, group A would pay the total amount, or if there was an equal number of participants in each group, they would share the cost 50/50, etc.

Thank you in advance.

 

[johnny51981]

Give this a shot:

=$A$1/SUM($A$2:$A$3)*$A2

 

[MrOllyR]

Give this a shot:

=$A$1/SUM($A$2:$A$3)*$A2

Thank you!