Question

Which of the following tables show/s a proportional relationship between “a” and “b”?
I

a	b
3	9
4	15

II

a	b
7	14
8	16

III

a	b
7	9
8	11

• A. II and III
  
• B. III
• C. II
• D. I

Answer 1

The correct option is C II

In table I:

a	b	$\frac{a}{b}$
3	9	$\frac{3}{9}=\frac{1}{3}$
4	15	$\frac{4}{15}$

Since $\frac{a}{b}$ is not constant, a and b are not in proportion.

In table II:

a	b	$\frac{a}{b}$
7	14	$\frac{7}{14}=\frac{1}{2}$
8	16	$\frac{8}{16}=\frac{1}{2}$

Here, $\frac{a}{b}$ is a constant.
Here, $\frac{1}{2}$ is the constant of proportionality.
Thus, it is a proportional relationship.


In table III:

a	b	$\frac{a}{b}$
7	9	$\frac{7}{9}$
8	11	$\frac{8}{11}$

Since$\frac{a}{b}$ is not a constant, a and b are not in proportion.