One litre of a medicine is to be packed in small bottles, each one of which c 125ml of medicine. How many such bottles are needed?

According to question 

Amount of medicine to be packed = 1litre = 1000ml (convert litre to millilitre, so that all the unit would be same)

Medicine holding capacity of small bottles = 125ml

Number of bottles needed to pack 1litre/1000ml medicine is = 1000 / 125 = 8 bottles

Check: 1 bottle contains 125-liter medicine

             8 bottles contains (8 x 125) = 1000