 
A young man I know had a used motorbike valued at $10,000 which he decided to sell. He figured he would add 10% to the price when he advertised it, and then offer a 10% discount if anyone was interested. That way he hoped to sell it easily and get back the $10,000 he paid for it.
Unfortunately he lived up to his word, and was forced to accept just $9900 for the bike. Do you know why? This is what I had to explain to him. He added 10% to the price, and then deducted 10% from the price. But the two prices were different! He first added 10% of $10,000, making his asking price $11,000. Then he offered a 10% discount on $11,000, which amounted to $1100, making the final price $9900! Since percents are a grade eight math topic, he should have known this! I charged him $100! |