60.2k views
5 votes
Large drinks cost $2.75 each and medium drinks cost $2.15 each. A restaurant sold 52 drinks yesterday and took in a total of $131.60. How many medium drinks did they sell?

User Eryrewy
by
8.0k points

1 Answer

3 votes

To solve this type of question we need to form 2 equations of 2 variables and solve them to find the 2 variables

Let x is the number of the large drinks and y is the number of the medium drinks

Since the restaurant sold 52 drinks, then


x+y=52\rightarrow(1)

Since the cost of the large drink is $2.75 each, then

The cost of the large drinks is 2.75(x)

Since the cost of the medium drink is $2.15 each, then

The cost of the medium drinks is 2.15(y)

Since the total cost of them is $131.60, then

Add 2.75(x) and 2.15(y) and equate the sum by 131.60


\begin{gathered} 2.75(x)+2.15(y)=131.60 \\ 2.75x+2.15y=131.60\rightarrow(2) \end{gathered}

Now we have a system of equations to solve it

Multiply equation (1) by -2.75 to make x equal in values of the two equations and different in signs to eliminate it


\begin{gathered} (-2.75)x+(-2.75)y=(-2.75)(52) \\ -2.75x-2.75y=-143\rightarrow(3) \end{gathered}

Add equations (2) and (3)


\begin{gathered} 2.75x+2.15y+(-2.75x)+(-2.75y)=131.60+(-143) \\ (2.75x-2.75x)+(2.15y-2.75y)=131.6-143 \\ 0-0.6y=-11.4 \\ -0.6y=-11.4 \end{gathered}

Divide both sides by -0.6


\begin{gathered} (-0.6y)/(-0.6)=(-11.4)/(-0.6) \\ y=19 \end{gathered}

They sold 19 medium drinks yesterday

User Rachid Loukili
by
9.0k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories