Introduction to Ratios and Proportions Flashcard

Front

What is a ratio?

Back

A way to compare two or more quantities by dividing them.

Front

What does the ratio 5:3 represent in terms of hardbound and paperback books?

Back

For every 5 hardbound books, there are 3 paperback books.

Front

If there are 75 hardbound books, how many paperback books are there if the ratio is 5:3?

Back

45 paperback books.

Front

What is a proportion?

Back

An equation that states that two ratios are equal.

Front

Solve for n in the proportion 8 : 19 = 14 : n.

Back

n = 33.25.

Front

If 5:7 is a proportion, what is the value of x in the ratio 15:x?

Back

x = 21.

Front

Back

12.

Front

How do you find a missing value in a proportion?

Back

Cross-multiply and solve for the unknown.

Front

What is the cross-multiplication method?

Back

In a proportion a:b = c:d, cross-multiply to get a*d = b*c.

Front

If the ratio of boys to girls in a class is 2:3, how many girls are there if there are 10 boys?

Back

15 girls.