Practice the questions of McGraw Hill Math Grade 8 Answer Key PDF Unit Test Lessons 15–17 to secure good marks & knowledge in the exams.
McGraw-Hill Math Grade 8 Unit Test Lessons 15–17 Answer Key
Question 1.
Manny is going to replace the trim around the windows in his house. The trim for each window measures 10\(\frac{1}{2}\) feet. If Manny has 15 windows in his house, how many inches of trim does he need to replace?
Answer:
1890 in.
Explanation:
The trim for each window measures 10\(\frac{1}{2}\) feet.
10\(\frac{1}{2}\)
1 feet = 12 inches
Half feet = 6 inches.
= 10 x 12 + 6
= 126 inches
If Manny has 15 windows in his house,
126 x 15 =1890 inches.
Question 2.
Annie’s fish tank holds 39\(\frac{1}{2}\) gallons of water. She is using a 1 quart container to fill the tank. How many full containers will Annie need to fill the tank?
Answer:
158 containers full.
Explanation:
1 gallon = 4 quarts
39\(\frac{1}{2}\) = x
convert mixed fraction in to improper fraction
39\(\frac{1}{2}\) = \(\frac{79}{2}\)
\(\frac{79}{2}\) x 4
= \(\frac{79 x 4}{2}\)
= 79 x 2
= 158 full containers will Annie need to fill the tank.
Question 3.
Florence weighed boxes for the shipping department. The first box weighed 196 ounces. The second box weighed 13\(\frac{3}{8}\) pounds. Which box weighed more?
Answer:
The second box 13\(\frac{3}{8}\) vs 12.25 lb
Explanation:
The first box weighed 196 ounces.
1 pound = 16 ounces
first box weighed 196 ounces
= \(\frac{196}{16}\)
=12.25 lb
The second box 13\(\frac{3}{8}\) is weighed more
Question 4.
Mandie plans to paint the side of her barn. The side measures 10 meters long arid 5.5 meters high. How much area does Mandie need to cover with paint?
____________ square meters
Answer:
55 square meters.
Explanation:
The side measures 10 meters long arid 5.5 meters high.
Area of the side of her barn to paint A
A = length x width
A = 10 x 5.5
A = 55 square meters
Question 5.
What is the area of the rectangle? ______________
What is the perimeter of the rectangle? ____________
Answer:
Area 132 sq ft,
Perimeter 46.
Explanation:
The area of the rectangle = l x b
1 ft = 12 in
132 in = 132/12 = 11 ft
A = 12 x 11
A = 132 sq ft
Perimeter is P = 2(Length + Width)
P = 2(12 + 11)
P = 2(23)
P =46 sq ft
Question 6.
What is the area of the right triangle?
_____________ square feet
What is the perimeter?
____________ inches
Answer:
Area 54 sq ft,
Perimeter 432 inches.
Explanation:
Area of a triangle A = (1/2) base x height
A = 1/2 x b x h
A = 1/2 x 9 x 12
A = 54 sq ft
Perimeter of a trangle is sum of 3 sides.
P = 9ft + 12 ft + 180in
P = (9 + 12) 12 + 180 in
P = 252 + 180
P = 432 in
Question 7.
What is the area of the base of the rectangular box?
_____________ square feet
Answer:
7.5 sq ft.
Explanation:
Area of a rectangle A = length x width
A = l x w
L = 36/12 = 3 ft
A = 3 x 2 \(\frac{1}{2}\)
A = 3 x \(\frac{5}{2}\)
A = \(\frac{15}{2}\)
A = 7.5 sq ft
Question 8.
A spacecraft must travel 24.1 kilometers per second to leave the Earth’s atmosphere. How far does the spacecraft travel in a minute?
In an hour? _____________________
In a day? _________________
Answer:
1446 km in an minute.
86,760 km in a hour.
2,082240 km in a day.
Explanation:
A spacecraft must travel 24.1 kilometers per second to leave the Earth’s atmosphere.
1 minute = 60 sec
24.1 x 60 = 1,446 km per minute
1 hour = 60 minutes
1,446 x 60 = 86,760 km
1 day = 24hrs
86,760 x 24 = 2,082,240 km
Question 9.
A school banner is 5.5 meters in length and 1,850 millimeters in width. How much fabric was used to make the banner?
_____________ sq cm
Answer:
101750 sq cm
Explanation:
A school banner is 5.5 meters in length and 1,850 millimeters in width.
convert 5.5 meters in cm,
1m = 100 cm
5.5 x 100 = 550 cm
1,850 millimeters in width
1,850/10 = 185 cm
Area = Length x Width
A = 550 x 185
A = 101750 sq cm
Question 10.
Blanche has three cans of paint to mix. One can holds 1,957 milliliters of paint, the second can holds 115.6 centiliters of paint, and the third can holds 3.9 liters of paint. How much paint will Blanche mix?
______________ liters
Answer:
7.013 Lits
Explanation:
One can holds 1,957 milliliters of paint
1957/1000 = 1.957 liters
Second can holds 115.6 centiliters of paint,
115.6/100 = 1.156
The third can holds 3.9 liters of paint.
3.9 liters
Total paint will Blanche mix
3.9 + 1.156 + 1.957
= 7.013 liters
Question 11.
What is the area of a triangle with sides of 12 cm, a base of 6 cm, and a height of 8 cm?
______________ sq cm
What is the perimeter of the triangle?
Answer:
Area = 24 sq cm.
Perimeter = 30 cm.
Explanation:
Area of Triangle A = (1/2) x 3 x 8
A = 12 x 2
Area of triangle = 24 sq cm
Question 12.
Frank walked around the entire rectangular school playground, which measures 126 meters by 6,500 centimeters. How far did Frank walk?
____________ meters
What is the area of the school playground?
_____________ square meters
Answer:
Distance = 382 meter;
Area = 8190 sq m.
Explanation:
A rectangular school playground,
which measures 126 meters by 6,500 centimeters
6500/100 = 65 meters
Frank walk is the perimeter of the rectangle P.
P = 2(length + width)
P = 2( 126 + 65)
Distance = 382 meter Frank walked.
Area of a rectangular school playground,
A = length x width
A = 126 x 65
Area = 8190 sq m.
Question 13.
What is the area of a rectangle that measures 4.6 meters in width, and 5.5 meters in length?
_______________ square meters
Answer:
25.3 sq m.
Explanation:
The area of a rectangle that measures 4.6 meters in width, and 5.5 meters in length.
Area of a rectangle = length x width
A = 4.6 x 5.5
A = 25.3 sq m
Question 14.
The average player on the soccer team weighs 165 pounds. About how much is that in kilograms?
Answer:
75 kg
Explanation:
The average player on the soccer team weighs 165 pounds.
1 kg = 2.2 pounds
x kg = 165 pounds
x = 165/2.2 =75 kg
Question 15.
The average pickup truck has a gas tank that holds 95 liters of gasoline. How much is that in quarts and in gallons?
_____________ quarts
_____________ gallons
Answer:
About 100 quarts;
25 gallons.
Explanation:
A gas tank that holds 95 liters of gasoline.
1 gallon = 3.8 liters
95 / 3.8 = 25 gallons
1 liter = 1.06 quarts
95 liter = 95 x 1.06
= 100 quarts
Question 16.
Pauline was looking for lawn-mowing jobs for the summer. She surveyed the neighborhood and found out that the average lawn measured 60 feet by 45 feet. What is the area in square feet?
_____________ sq ft
About how much is the total area in square meters?
______________ sq meters
Answer:
2700 sq ft;
About 250 sq m.
Explanation:
The average lawn measured 60 feet by 45 feet.
Area = Length x width
A = 60 x 45
A = 2700 sq ft
as we know..
1 meter = 3.28 ft
60 ft = 18.28 m
45 ft = 13.7 m
The area in square meters,
Area = Length x width
A = 18.28 x 13.7
A = 250 sq m
Question 17.
The distance of a flight from Cleveland to New Orleans is about 1,250 miles. The average speed of a commercial airliner is about 830 kilometers per hour. About how long will it take to fly from Cleveland to New Orleans?
______________ hours
Answer:
About 2\(\frac{1}{2}\) hours.
Explanation:
The distance of a flight from Cleveland to New Orleans is about 1,250 miles.
The average speed of a commercial airliner is about 830 kilometers per hour.
1 mile = 1.6 km
1250 miles = 1250 x 1.6 = 2000 km
time = distance / speed
time = 2000/ 830
2\(\frac{1}{2}\)
Question 18.
The air-conditioning company suggests that people keep the temperature in their homes between 22 and 28 degrees Celsius during the summer. What is the temperature range in degrees Fahrenheit?
Answer:
71.6° to 82.4°F
Explanation:
To convert temperatures in degrees Fahrenheit to Celsius,
multiply by 1.8 (or 9/5) and add 32
The formula for converting Celsius to Fahrenheit is
F = 1.8 x C + 32
F = 1.8 x 22 + 32
F = 39.6 + 32
F = 71.6°F
F = 1.8 x C + 32
F = 1.8 x 28 + 32
F = 50.4 + 32
F = 82.4°F
Question 19.
What is the area of the base of the rectangular solid shown?
Answer:
32 sq m.
Explanation:
Area of the base of a rectangle = Length x Width
A = l x w
A = 8 x 4
A = 32 sq cm
Question 20.
What is the area of the triangular face on the figure shown?
Answer:
48 sq in.
Explanation:
Area of the triangular face = (1/2) x base x height
A = (1/2) x 12 x 8
A= 48 sq in.
Question 21.
In track and field, the standard middle distance event is the 5,000 meter race. About how many feet, is 5,000 meters?
______________ feet
Answer:
16,500 ft
Explanation:
Standard middle distance event is the 5,000 meter race.
About how many feet, is 5,000 meters,
1 meter = 3.3 ft
5000 meters =
5000 x 3.3 = 16,500 ft
Question 22.
A body temperature of 103.6° F is considered an extremely high fever. What temperature is that in Celsius?
Answer:
39.8°C
Explanation:
To convert temperatures in degrees Fahrenheit to Celsius,
subtract 32 and multiply by 0.5556 (or 5/9).
Fahrenheit and Celsius are the same at -40°.
The formula for converting Fahrenheit to Celsius is
C = 5/9(F-32).
C = 5/9(103.6 – 32)
C = 39.8°C