[Question]: The local salon offers mani/pedis for $40.00. They are running a Mother's day special and offering 25% off their regular rate. Charlotte is treating herself, her daughter and 3 granddaughters to a spa day. How much will Charlotte spend on 5 mani/pedis?
[Answer]: A mani / pedi is $40.00 and they are offering 25% off so that's 40 * .25 = $10.00 discount. The mani / pedi is $40.00 and there is a $10.00 discount so each one is 40 - 10 = $30.00. Charlotte is treating herself and 4 other people for a total of 5 people at $30.00 each so it will cost 5 * 30 = $150.00.
So the answer is 150.

[Question]: Bernie has a collection of 18 unique postcards. He decided to sell half his collection for $15 per postcard. After he has successfully sold his postcards he decided to spend all the earned money to buy new postcards for $5 each. How many postcards does Bernie have after all his transactions?
[Answer]: Half of Bernie's collection means 18 * 0.5 = 9 postcards. So he was able to sell 9 postcards for 9 * 15 = $135. He decided to spend all of his money on new postcards for $5 each, so he was able to buy 135 / 5 = 27 new postcards. This means Bernie has 9 + 27 = 36 postcards after all.
So the answer is 36.

[Question]: A jet travels 580 miles in 2 hours. At this rate, how far could the jet fly in 10 hours?
[Answer]:
In one hour the jet could travel 580 miles / 2 hours = 290 miles. In 10 hours the jet could fly 290 miles * 10 = 2900 miles.
So the answer is 2900.