40% of the fish in a pond are goldfish and the rest are koi. the number of goldfish is g. the farmer then increases the number of koi by 10%. how many koi are there in the pond, in terms of g, now?

So 40% is goldfish
therefor 100-40=60% is koi
40%=g
koi goes up by 10%
that means 10% of the koi
10% of 60=1/10 of 60=6
60 goes up to 66
so we have
g is to 40 as is xg is to 66
g:40=xg:66
g/40=xg/66
multiply both sides by 66
66g/40=xg
divide both sides by g
66/40=x
33/20=x
there is (33/20)g koi now