Hello house, please for those who have started pracitising with the practise materials, has anyone noticed any discrepances? Please look at the 6th question on practise test 1. Have u noticed how percentage profit is being calculated as: 'profit/selling price X100'? Every test book I have ever seen and even internet sources calculate profit as; 'profit/cost price x 100'. What wud u guys advice we do; work with the mckinsey formular in preparation for thier test or use the right thing? I mean, its possible dat its an oversight on their part, we cannot know. Please I need contributions. Thanks.