The store's mark up is added to their cost price.The percentage discount is actually the stores mark up, not really a discount.
If they gave their mark up away as discount they'd make no money.
Eg;
Store buys rad at 50% discount of manufacturer's price list ie £50.
They want 25% mark up, which equates to list less 38.5%. They'll probably round that to 38% off the manufacturer's price list.
Or they may inflate the manufacturer's price list by 8% and offer it at, say, 42% off their own list. 42% looks better on paper.
Or they may sell it at £62.00 net.
All 3 methods can work out at roughly the same selling price.
