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Many restaurants suggest tipping based on a pre-coupon / pre-discount total.The original bill would have been something like $40 with a 50% discount in a county with 9% sales tax on prepared foods.(sales tax is calculated with regard to the subtotal pre-coupon amount in the case of a percentage decrease and added after the discount took place).Tip is often calculated against the pre-coupon,post-tax amount.

40*1.09 – .5*40 = 23.60 (total as it appears on check) 40*1.09*0.15 = 6.54 (suggested tip amount for 15%) 40*1.09*0.17 = 7.84 (suggested tip amount for 18%) 40*1.09*0.20 = 8.72 (suggested tip amount for 20%)

So,my guess was off by a few pennies somewhere.Perhaps the sales tax in the area isn't exactly 9%,or perhaps it was a $39.99 meal with a 50% off coupon,but you get the idea.

Many restaurants suggest tipping based on a pre-coupon / pre-discount total.The original bill would have been something like $40 with a 50% discount in a county with 9% sales tax on prepared foods.(sales tax is calculated with regard to the subtotal pre-coupon amount in the case of a percentage decrease and added after the discount took place).Tip is often calculated against the pre-coupon,post-tax amount.

40*1.09 – .5*40 = 23.60 (total as it appears on check)

40*1.09*0.15 = 6.54 (suggested tip amount for 15%)

40*1.09*0.17 = 7.84 (suggested tip amount for 18%)

40*1.09*0.20 = 8.72 (suggested tip amount for 20%)

So,my guess was off by a few pennies somewhere.Perhaps the sales tax in the area isn't exactly 9%,or perhaps it was a $39.99 meal with a 50% off coupon,but you get the idea.

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Uuuuuuuuuuuuuuuuuuuuuuuuuuuuu!!!tough guy!!!!thats just a customer copy….

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It's easier than jihkro's solution.They got $19.90 off,but calculated the tip based on the full amount.No VAT speculation needed.

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