Question 1025153
So calculate how many kilos you can make with the Colombian since you use more of it. 
Each kilo uses 2/5 kilo of Brazilian and 3/5 kilo of Colombian.
{{{N=(25)/(3/5)=41&2/3}}}
So you can make 41 kilos of the mix and you'll have 2/5 of a kilo left over of the Colombian.
{{{41(2/5)=16&2/5}}}
{{{20-16&2/5=3&3/5}}}
You'll have {{{3&3/5}}} kilos of Brazilian left.