Question 10 on the MAT0020/24C Beginning Algebra State Exam

Solve a Word Problem

 

10.  The length of a rectangle is 2 feet more than the width.  The perimeter of the rectangle is 72 feet.  Find the length.                                                               

 

A.  19 feet                    B.  17 feet                    C.  37 feet                    D.  35 feet

 

Solution:

 

The first step is to translate the statements into algebraic expressions.

The length of a rectangle is 2 feet more than the width would be represented by: x + 2

The width would be represented by: x

Here is a visual representation:

                               Text Box: x+2

                        Text Box: x
Text Box: x+2

Text Box: x

 

                                   

 

 

 

The next step is to create an algebraic equation to solve for x. 

Since the perimeter is the sum of the sides, the equation would be:

 

(x) + (x + 2) + (x) + (x + 2) = 72

 

The next step is to combine like terms:

 

4x + 4 = 72

 

Then solve for x:

 

x = 17

 

Since x is the width, then the width is 17.  The length is x + 2, so the length is 19.

 

The answer is 19.

 

Note:  You can check your solution by substituting it back into your algebraic equation.

 

 

Practice Problems for Question 10

Solve a Word Problem

Solutions explained in following pages.

 

1.  A CD is priced at $15.00, but it is on sale for 20% off.  What is the sale price of the CD?

 

a.   $3.00                     b.   $10.00                   c.   $18.00                   d.   $12.00

 

 

 

 

2.  If a sony play station costs $250 after a 15% discount, what was the original cost?

 

a.  $294.12                  b.  $212.50                  c.  $287.50                  d.  $399.46

 

 

 

 

3.  If a palm pilot costs $1300 after a 20% increase in price, what was the original cost?

 

a.   $1625.00               b.   $1083.33               c.  $1560.00                d.  $1040.00

 

 

 

 

4.  Find the simple interest percent if you invested $1000.00 for 5 years and you received $500.00 in interest.

 

a.  20%                        b.  50%                        c.  10%                        d.  40%

 

 

 

 

5.  The width of a rectangular garden is 8 meters less than its length.  Its perimeter is 76 meters.  Find the length of the garden.

 

a.  23 meters                b.  76 meters                c.  345 meters              d.  15 meters

 

 

 

 

6.  The perimeter of a triangle is 51 inches.  The length of the middle side is 5 inches more than the length of the smaller side and the largest side is 4 inches less than three times the length of the smallest side.  Find the length of the middle side.

 

a.  10 inches                 b.  15 inches                 c.  26 inches                 d.  5 inches

 

 

 

 

7.  Two shrimp boats start from the same port at the same time, but they head in opposite directions.  The slower boat travels 15 knots per hour slower than the fast boat.  At the end of 12 hours, they were 600 nautical miles apart.  How many nautical miles had the slow boat traveled by the end of the 12-hour period?

 

a.  210 nautical miles                 b.  17.5 nautical miles

c.  2.5 nautical miles                  c.  390 nautical miles

 

 

 

 

Solutions to Practice Word Problems

 

1.  D

 

To find the discount you multiply the original price by the percent of the discount.

 

So, the discount is $15.00(0.20) = $3.00.

 

To find the sale price you subtract the original price from the discount.

 

So, to find the sale price you take 15.00 – 3.00 = 12.00.  The sale price is $12.00.

 

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2.  A                                                                                        Check

 

Original Cost – Discount = Sale Price                           294.12 - .15(294.12) = 250

 

X - .15X = 250                                                                        294.12 – 44.12 = 250

 

1X - .15X = 250                                                                      250 = 250

 

.85X = 250

.85        .85

 

X = 294.12

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3.  B

 

Original Cost + Increase = New Price   Check:   1083.33 + .20(1083.33) = 1300

 

            X + .20X = 1300                                                         1083.33 + 216.67 = 1300

           1X + .20X = 1300                                           

                                                                                                1300 = 1300

            1.20X = 1300

            1.20       1.20

 

X = $1083.33

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4.  C

 

The formula to find simple interest is:  Interest = Principal x Rate x Time (I = P*R*T)

 

The information gives would lead to:  500 = (1000)X (5)

 

Then simplify:  500 = X(5000)

 

Then solve for x by dividing both sides by 5000:  500/5000 = X(5000)/5000

 

X = 0.10, the simple interest percent would be 10%.

 

Check:             500 = 1000(0.10)(5)

                        500 = 500

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5.  A

                                                            W - 8                                       Width:  W -8

                                                                                               

                                                Length:  W

                        W                                                                    W       

Perimeter:  76

                                                                                               

 

 

 

 

W - 8

 

Equation:  W + W - 8 + W + W - 8 = 76                                             Width:  23 – 8 = 15

 

Combine Like Terms:  4W - 16 = 76                                                    Length: 23

                                           + 16  +16

                                    4W      =     92                         Check:  15 + 23 + 15 + 23 = 76

                                    4                  4                                                              76   = 76

 

Solve:                           W = 23           

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6.  B

Small:  X                                                                                             

Middle:  X + 5

Large:  3X - 4                                                  X                                 X + 5

Perimeter: 51

 

 

 

                                                                                    3X - 4

 

The equation will be: X + X + 5 + 3X - 4 = 51                        

 

Combine like terms:  5X + 1 = 51                                                        

Solve:                               - 1   - 1

                                    5X      = 50                              Check: 10 + 10 + 5 + 3(10) - 4 = 51

5             5                                           10 + 15 + 26 = 51

                                                                                                 25 + 26 = 51

                                    X   =   10                                                    51   = 51

 

Small:  X = 10

Middle:  10 + 5 = 15

Large:  3(10) - 4 = 26

________________________________________________________________________

7.  A

Type

D

R

T

Fast Boat

12X

X

12

Slow Boat

12(X-15)

X

12

Total

600

 

 

 

Fill in the 4 x 4 chart with the given information.

To fill in the distance column use the formula Distance = Rate x Time

You now have the formula:

12X + 12(X - 15) = 600

Distributive Property:  12X + 12X -180 = 600

Combine Like Terms:  24X - 180 = 600

                                             +180   +180

Solve for X:                  24X          = 780

                                    24                 24                                  

                                          X     =  32.5

Substitute X into the chart and answer the question:

Type

D

R

T

Fast Boat

12(32.5) =390 miles

32.5 knots

12

Slow Boat

12(32.5-15) = 210 miles

32.5-15 = 17.5 knots

12

Total

600 miles

 

 

 

The answer from the chart is the slow boat traveled 210 miles.