How much would a plumber's bill for £452 before tax be after 17½% VAT was added? How much would a restaurant bill for £62.50 be after a 10% loyalty card bonus was subtracted?

A plumber's bill for £452 plus 17½% VAT would be £531.10. To add 17½% we first convert to 0.175. We now add this to 1.00 to give 1.175. We now multiply 452 × 1.175 = 531.1

A restaurant bill for £62.50 be after a 10% loyalty card bonus was subtracted would be £56.25. To subtract 10% we convert 10% to 0.10. We subtract from 1.00 to give 0.90. We multiply 62.50 × 0.90 = 56.25. (Then you leave the 10% as a tip.)

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Last updated: 3 October, 2007.