Ratios
What is a ratio?
Comparison of two numbers that use division.
A bike travels 54 miles in 4 hours.
Write it as a rate (fraction):
54 miles/4 hours
Alex can run 24 miles in 3 hours. What is his average speed in miles per hour? (m/h)
8 mph
Find the missing proportional number.
4 : _____ = 20 : 15
3
What is the constant of proportionality in the equation y=5x?
k=5
Three (3) ways you can write ratios:
Colons (;), Word (to), Fractions (/)
You buy 5 pounds for $35.
Write this as a rate (fraction):
$35/5
Jessica earned $14 by babysitting for 4 hours. How much is she getting paid per hour? ($/h)
$3.50 per hour
Find the missing proportional number.
2 : 9 = 12 :_____
54
What is the constant of proportionality in the equation y=0.41x?
y=0.41x
Write the ratio that compares how many letter R's there are to how many letter Q's there are:
R R Q R Q Q Q R R R R
7:4, 7 to 4, or 7/4
At what rate did Bonnie type her paper if she typed a 2 page report in 45 minutes?
45 minutes/2 pages
Mr. Jones teaches 154 students in 7 classes. How many students does he have per class?
22 students per class.
Solve for x:
1/9 = x/108
x=12
What does (0,0) represent on a graph?
origin
In a class of 20 students, 12 are girls.
Write the ratio of the number of girls to total students.
12:20
Ivy's Fresh Eggs transports its eggs in crates. It takes 3 trucks to carry 60 crates.
Find the rate of the number of crates that 12 trucks can carry.
240 crates
What is the cost of one egg if a dozen eggs cost $1.08?
$0.09 per egg.
Ann's car can travel 228 miles on 6 gallons of gas
Write an equation to represent the distance, y, in miles Ann's car can travel on x gallons of gas. (y=kx)
y=38x
In order for a line to be proportional, it needs to be two things:
1.) Starts from the origin (0,0)
2.) A straight line
In a class of 20 students, 12 are girls and the rest are boys.
Write the ratio of the number of boys to the number of girls.
8:12, 8 to 12, or 8/12
An arts academy requires there to be 3 teachers for every 75 students and 6 tutors for every 72 students. How many tutors does the academy need if it have 120 students?
10 tutors
Mike read 1/4 of the newspaper in 1/3 of an hour. How long did it take him to read the whole paper? (h/n)
1.33 repeat hours per newspaper.
Ann's car can travel 228 miles on 6 gallons of gas
Ann's car used 7 gallons of gas during a trip. How far did Ann drive?
266 miles on 7 gallons
Mary ran 2 miles in about 23 minutes. If she continued at the same pace, how long will it take her to run 10 miles?
115 minutes to run 10 miles