Question

A salad dressing is made up of 2 parts vinegar to 3 parts oil. How much vinegar should be used with 50 mL of oil?

Answer 1

Hint: We have given the ratio of vinegar and oil which is $2:3$. Now, by using this ratio we will calculate the quantity of vinegar. We will use the concept of ratio and proportion to solve this question. By equating the ratio we get the desired answer.

Complete step-by-step solution:
We have been given that a salad dressing is made up of 2 parts vinegar to 3 parts oil.
We have to find the quantity of vinegar used with 50 mL of oil.
Let us assume that x mL vinegar is used with 50 mL of oil.
As given in the question those 2 parts vinegar is used with 3 parts oil.
Now, we get the ratio of vinegar to oil will be
$\Rightarrow 2:3$
Now, if x mL of vinegar is used with 50 mL of oil. Then the ratio will be
$\Rightarrow \dfrac{2}{3}=\dfrac{x}{50}$
Now, simplifying the above obtained equation we will get
$\Rightarrow 50\times 2=3\times x$
Now, simplifying the above obtained equation we will get
$\begin{align}
  & \Rightarrow 100=3x \\
 & \Rightarrow x=\dfrac{100}{3} \\
 & \Rightarrow x=33\dfrac{1}{3}\text{ mL} \\
\end{align}$
Hence we get that $33\dfrac{1}{3}\text{ mL}$vinegar should be used with 50 mL of oil.

Note: Be careful while taking the ratio. As we use the ratio 2 parts vinegar to 3 parts oil, then we must have to write the quantity of vinegar at the numerator and quantity of oil to the denominator. If we reverse the values we get the incorrect answer.