Question

The given table shows the internet bill for a number of months. There is a proportional relationship between the number of months and the bill amount.

Bill amount $\left(\$\right)$	$a$	$24$	$36$	$b$
Number of months	$1$	$2$	$3$	$4$

Find the values of $a$ and $b.$

• A. $a=12,b=42$
• B. $a=18,b=48$
• C. $a=18,b=42$
• D. $a=12,b=48$

Answer 1

The correct option is D $a=12,b=48$

The constant of proportionality is:
$\frac{24}{2}=\frac{36}{3}=12$
Hence, $\frac{a}{1}=12$
$\Rightarrow a=12$
Similarly, $\frac{b}{4}=12$
$\Rightarrow b=12\times 4$
$\Rightarrow b=48$