by Cece
(Bakersfield California)
A stationery store sells a dozen ballpoints pens for $3.84, which represents a 20% discount from the price charged when a dozen pens are bought individually. How much does it cost to buy three pens?
Solution
Let x be the price of a dozen ballpoints pens without the 20% discount.
x - 20%x = 3.84
x - 0.20x = 3.84
0.80x = 3.84
x = 3.84/0.80
x = 4.8
4.8 is the price for 12 ballpoints pen with no 20% discount.
The price of 1 ballpoints pen is 4.8 / 12 = 0.4
The price of 3 pens is 3 × 0.4 = 1.2
Jul 20, 17 10:41 PM
A water tank is emptied at a constant rate. Initially, 36,000 gallons of water were in the tank. A the end of five hours, 16,000 gallons remained. How
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Jul 20, 17 10:41 PM
A water tank is emptied at a constant rate. Initially, 36,000 gallons of water were in the tank. A the end of five hours, 16,000 gallons remained. How