February Problem of the Day Estimation, Percentages, and Rates

February 1, 2014 Taxi fares depend upon the distance that is traveled and the number of passengers. Tony’s Taxi charges $3 for the first mile and $1 for each additional half mile (or fraction thereof). If the taxi ride is 5¼ miles, what is the fare? What if you had $15, how many miles could you travel? When traveling, transportation costs can add up, what are some costs associated with vacationing?

February 4, 2014 An odometer records the number of miles a car has traveled. When the Santos family left for Florida, the odometer read miles. When they arrived in Florida, it was miles. They drove 18.6 miles while they were in Florida. They returned home of the same roads they used for driving to Florida. If gasoline is $3.50/gal and their car gets 22 mpg, how much did it cost them for their trip? How could they have reduced their transportation costs?

February 5, 2014 A stack of recyclable newspaper 36 inches high will save one tree. If you save a stack of newspapers 14 feet high, about how many trees are saved? If you wanted to save 100 trees, how many feet high would the stack have to be? What is the ratio between the height of the newspaper stack in feet and the number of trees saved?

February 6, 2014 A printing press that prints money can print 8,000 sheets of 32 bills every hour. If five- dollar bills are printed, what is the value of the money printed during an 8-hour shift? What is the ratio of sheets per minute?

February 7, 2014 At a Dollar-Day Sale everything in the designated section of the store is priced at a dollar or in multiples of a dollar. Mary and Joe went shopping during this sale. The cost of the items they decided to buy was $25. They must pay sales tax at 6¢ per dollar or 6%. What is the total cost of their purchase? If $10 of the $25 was clothing, how does that change the PA sales tax charge? What is their total purchase with this change?

February 8, 2014 A successive discount is a discount after a previous discount has been made. Successive discounts can lead to big savings. The price of a jacket is reduced 40%. For one day only the reduced price is reduced another 10%. Is this the same as a 50% discount? Use an example to support your answer.

February 11, 2014 Buying things on sale is a great way to save money. A CD is marked 30% off the original price. The sale price is $ Ignoring the sales tax, find the original price of the CD. Explain why you think it is more cost effective to purchase CD’s or download specific songs.

February 12, 2014 A “tip” is a gratuity, or a payment for good service. In most cases a tip of 15%, before sales tax is added, is acceptable. Three people went to lunch together. The bill came to $23.91, plus 6% sales tax. They decided to leave a 15% tip and divide the cost of lunch equally, each paying the same amount. How much would each person pay for lunch with tip and tax? Round to the nearest cent. In the high-end city restaurants, the expected tip can be higher, even up to 25%. What is your opinion about tipping for service?

February 13, 2014 If an investment increases at about the same rate each year, the Rule of 72 may be used to estimate how many years it will take for the original amount of money to double. For example, if $1,000 is invested at an interest rate of 6%, divide 72 by 6 (6% x 100 = 6). Since the quotient is 12, it would take 12 years for the $1,000 to double. Try it with $6,000 and 10.5% - about how many years would it take to double? How does this knowledge affect how you save money for things you want?

February 14, 2014 Memorabilia are the kinds of things that everybody once had, but few can find years later. Because they are hard to find, such items may become worth much more money than they originally cost, TV Guide, for example. Assuming an issue of TV Guide that once sold for $0.15 now sells for $7, what is the percent of increase? What commonplace items of today do you think will become collectable in 20 years?

February 15, 2014 Henry Ford worked to produce an inexpensive, universal car. When introduced in 1908, his Model T retailed for $850, but by 1924 – because of mass production - it was selling for $250. Find the percent of decrease and round your answer to the nearest percent. The average net income in 1928 was $6, per year. If you could save $5 a week to buy a $250 car, how long would it take you? How much would you have to save each week to buy a new economy car today?

February 19, 2014 Prepackaging is common in supermarkets. A prepackaged item has been cut, weighed, and priced to make shopping more convenient for customers. According to the label on the package of turkey, the turkey weighs pounds. It is priced $0.79 per pound. Find the cost of the turkey and round your answer up to the penny. If you buy in bulk, you get a lower price per pound. If you buy 20 pounds the cost is $0.60 per pound, how much more will it cost you? Is it cost effective to purchase in bulk?

February 20, 2014 Environmentalists estimate that during a lifetime, an average person will throw away garbage that is equivalent to 600 times his or her adult weight. Using this information, about how much would an adult who threw away 54 tons of trash weigh? What kinds of waste products are produced in your industry? What is the cost of their removal or recycling?

February 21, 2014 Bamboo, a tall, treelike grass found in tropical or semitropical regions, may grow as much as 1.5 feet per day. It may reach a maximum height of 120 feet. If bamboo grows at its fastest rate, how long would it take to reach its maximum height? Using bamboo is considered environmentally positive. Do you agree with this and why?

February 22, 2014 Kathy plans to cook a turkey dinner for her family. The turkey, which weighs about 16 pounds, takes about 6 hours to cook. Before serving, however; it must set 30 minutes. About what time should Kathy start to cook the turkey if she wants dinner to begin at 7 PM? Why is timing important in preparing food?

February 25, 2014 Math Textbook vs. Real World. Suppose Sam runs a lap around the high school track in 2.5 minutes. How long will it take him to run 6.5 laps. The math textbook answer would be minutes. In real life this answer is possible, but unlikely. What would you estimate as a realistic time for the 6.5 laps? Why is there a difference between the math textbook and real life?

February 26, 2014 An average adult’s heart beats 80 times per minute. An average canary’s heart beats 130 times in 12 seconds. Of the two heartbeats above, which is faster, and about how many times as fast is it? Does your answer make sense? Explain why or why not.

February 27, 2014 The escape velocity is the minimum velocity (speed) that an object needs to overcome the pull of gravity from another object. For a spacecraft to leave Earth, it would need to achieve an escape velocity of about 7 miles per second. This is faster than the speed of sound, which travels at about 760 miles per hour (at 0°C). Express the Earth’s escape velocity in miles per hour. About how many times the speed of sound is this? Explain how you solved this problem.

February 28, 2014 A light year is the distance a ray of light travels in one year (about 186,000 miles per second). After the sun, the nearest star to the Earth is Proxima Centauri at about 4.3 light years away. A parsec is another way to measure great distances in space. Proxima Centauri is about 1.3 parsecs from Earth. About how many parsecs equal a light year? About how many light years equal a parsec? Do your answers make sense?