A tent is sold for £120.70 after having been reduced by 15%.

how much did the tent cost before the reduction?

The original price of the tent is 100%. Original price = 100%. Second-hand price = 100% - 15% = 85%. So £120.70 = 85% of the original price. So 1% of original price = £120.70 : 85 Original price = 100% = 100 x 1% = 100 x (£120.70 : 85) = £142