by Graham Smithers
John bought three types of pond plant – oxygenating, floating and lilies – sold in packs of eight, four and two respectively. All the packs were the same price and he ended up with the same number of plants of each type. He then recovered his costs by selling some of the packs for 25% more than they cost, leaving himself with exactly 50 plants among which lilies were the least in number.
How many of these were lilies?