Question

Dominique is buying water. She needs 2 liters. A​ half-liter of water costs ​$2.46. A 250​-milliliter container of water costs ​$1.48. What should Dominique buy so she gets 2 liters at the lowest​ price? Explain.

Answer 1

Answer:

$\fbox{\begin{minipage}{15em}A half-liter of water costs 2.46 \end{minipage}}$

Step-by-step explanation:

Dominique wants to buy $2$ liters of water.

Case 1:

A half-liter of water costs $2.46$.

The $2$ half-liters is $1$ liter => The cost of a liter of water ($A$) is calculated by multiply  the cost of $1$ half-liter by $2$:

$A = 2.46$ x $2$ = $4.92$

=> The cost of two liters: $A_{1}$ = $A$ x $2$ = $4.92$ x $2$ = $9.84$ $

Case 2:

A quarter-liter of water costs $1.48$.

The 4 quarter-liters is $1$ liter => The cost of a liter of water ($B$) is calculated by multiply the cost of $1$ quarter-liter by $4$:

$B = 1.48$ x $4$ = $5.92$

=> The cost of two liters: $B_{1} = 5.92$ x $2$ = $11.84$ $

Compare $A_{1}$ and $B_{1}$, the cost of second buying method is more expensive.

=> She should buy the water, in which a​ half-liter of water costs ​$$2.46$

Hope this helps!

:)