Problem Solving

Hello,

Can you please assist with this:

A manufacturer packages soap powder in containers of three different sizes. The amount of soap powder
in a full large container could fill exactly 3 of the medium containers or exactly 5 of the small containers. If an equal number of small and large containers are to be filled with the amount of soap powder that would fill 90 medium containers, how many small containers will be filled?

OA: 25

I am getting 54 though.

Let x be the amount of soap powder in a full large container.

This would fill 3 medium containers i.e. x/3
or 5 small containers i.e. x/5

If x/3 = 90 => x = 270

Hence, number of small containers = 270/5 = 54

Can you please tell me where I am going wrong here?

Thanks,
Sri