Question

The given table shows the amount of milk in milliliters $\left(x\right)$ required to make a given weight of a cake in kilograms $\left(y\right)$.

$\begin{array}{ccc}\text{Weight of cake (kg)}& a& 2\\ \text{Amount of milk (mL)}& 125& b\end{array}$

The linear equation relating the two quantities in the table is $y=0.004x$.

Find the values of a and b.

• A. $a=0.5\text{kg},b=500\text{mL}$
• B. $a=0.5\text{mL},b=750\text{mL}$
• C. $a=0.25\text{kg},b=500\text{mL}$
• D. $a=0.25\text{mL},b=750\text{mL}$

Answer 1

The correct option is A $a=0.5\text{kg},b=500\text{mL}$

Equation, $y=0.004x$
Constant of proportionality $=\frac{y}{x}=0.004$
So, slope $=\frac{a}{125}$
$\Rightarrow a=0.004\times 125$
$\Rightarrow a=0.5\text{kg}$
Similarly, for slope $=\frac{2}{b}$
$\Rightarrow 2=0.004\times b$
$\Rightarrow b=500\text{mL}$