February Problem of the Day

1
February Problem of the Day

• Estimation, Percentages, and Rates

2
February 1, 2013

• Taxi fares depend upon the distance that is
  traveled and the number of passengers. Tonys
  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?

3
February 4, 2013

• An odometer records the number of miles a car has
  traveled. When the Santos family left for
  Florida, the odometer read 8765.2 miles. When
  they arrived in Florida, it was 9382.7 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?

4
February 5, 2013

• 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?

5
February 6, 2013

• 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?

6
February 7, 2013

• 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?

7
February 8, 2013

• 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.

8
February 11, 2013

• Buying things on sale is a great way to save
  money. A CD is marked 30 off the original price.
  The sale price is 12.60. Ignoring the sales tax,
  find the original price of the CD.

9
February 12, 2013

• 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.

10
February 13, 2013

• 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?

11
February 14, 2013

• 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?

12
February 15, 2013

• 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.

13
February 19, 2013

• 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 14.56 pounds. It is
  priced 0.79 per pound. Find the cost of the
  turkey and round your answer up to the penny.

14
February 20, 2013

• 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?

15
February 21, 2013

• 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 grow at its fastest rate, how
  long would it take to reach its maximum height?

16
February 22, 2013

• 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?

17
February 25, 2013

• 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 16.25 minutes. In
  real life this answer is possible, but unlikely.
  What would you estimate as a realistic time for
  the 6.5 laps?

18
February 26, 2013

• An average adults heart beats 80 times per
  minute. An average canarys heart beats 130 times
  in 12 seconds. Of the two heartbeats above, which
  is faster, and about how many times as fast is it?

19
February 27, 2013

• 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 0C). Express the
  Earths escape velocity in miles per hour. About
  how many times the speed of sound is this?

20
February 28, 2013

• 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?