Question 1074083: 1. A tent is on sale at a 30% discount. The regular price of the tent is $425. How much is the discount?
2. A car steroeo system that cost $625.50 is on scale with 20% discount. What is the sale price of the car stereo system
Answer by addingup(3677)   (Show Source):
You can put this solution on YOUR website! 1. The discount is 30% of 425. Multiply times 0.30 to get your answer.
2. The stereoeo (?) is on scale (?) with 20% discount:625.50*0.80 gives you your answer. Why? Because if 0.20 is the discount, 1-0.20 = 0.80
NOTE: Why if it's 30% we use 0.30? Because it's 30 percent, comes from the Latin per centum which literally means for every one hundred. So the discount is 30 for every one hundred. So you have two choices, your can multiply 30 times 4.25 (four one hundreds plus a fraction of 0.25 of one hundred) or you can take the 30 and bring it down to 1, you divide the 30/100 and that gives you the discount for every one dollar.
There is something called "convention". Convention is a general agreement about how something is usually done. Without convention we'd have chaos. In math, convention says that to calculate a percentage we bring the per-centum down to per-one.
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