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This essential trains for: SATI, GMAT, AMC8, Math Kangaroo 56, Math Kangaroo 78.
Summary
If a unit costs D dollars, the total to pay for N units is:
The commission that a salesperson earns is generally paid by the seller.
The table summarizes the relations between cost, commission, sales tax:
Sticker price: D  Professor Lidenbrock bought 45 ft.of gauge 1/4'' rope at 0.8 krona per foot and twice as much gauge 1/2'' rope at 1.5 krona per foot. How much was he quoted for the rope? 


Sales commission: c%  Based on the above quote, if Gunnar the salesperson was paid a 4% commission, how many kronas did he receive?  
Seller receives: S  Based on the quoted price and the sales commission, what is the net amount received by the seller "Gunnbjorns Fjeld Outfitters"?  
Sales tax: t%  If the Icelandic government charges 12% sales tax, what is the amount Professor Lidenbrock actually paid? 
(Professor Lidenbrock is a character from Jules Verne's "Voyage to the Center of the Earth.")
Discount: After a discount of 25% a pair of tickets for a blimp ride costs only $300. What is the price of a ticket without the discount?
Denote the regular price of the pair of tickets with x. 300 dollars represents only 75% of the regular price:
The price of a single ticket is:
Markup: After all its competitors went out of business, Solocast marked up all its packages by 10%. Now, a valued customer pays $3.59 more for a basic package. What is the price of a basic package?
Denote the old price by x. 10% of the old price represents the amount the price was marked up by:
The old price was:
The new price is: