+0  
 
0
170
1
avatar+586 

Betty goes to the store to get flour and sugar. The amount of flour she buys, in pounds, is at least 6 pounds more than half the amount of sugar, and is no more than twice the amount of sugar. Find the least number of pounds of sugar that Betty could buy.

 Aug 28, 2018

Best Answer 

 #1
avatar+21848 
+5

Betty goes to the store to get flour and sugar.
The amount of flour she buys, in pounds, is at least 6 pounds more than half the amount of sugar,
and is no more than twice the amount of sugar.
Find the least number of pounds of sugar that Betty could buy.

 

Let \(y\) = flour
Let \(x\) = sugar

 

\(\begin{array}{|rcll|} \hline y &\ge& 6+\dfrac x2 \\ y &\le& 2x \\ \hline \end{array}\)

 

\(\begin{array}{|rcll|} \hline && & y \ge 6+\dfrac x2 \\ && & y \le 2x \\\\ \underline{x_{\text{min}}:} \\ 2x &=& 6+\dfrac x2 \\\\ 2x-\dfrac x2 &=& 6 \\\\ \dfrac32\cdot x &=& 6 \\\\ x &=& \dfrac23 \cdot 6 \\\\ \mathbf{ x} & \mathbf{=} & \mathbf{4\ \text{pounds}} \\ \hline \end{array}\)

 

The least number of pounds of sugar that Betty could buy are \(\mathbf{4\ \text{pounds}}\).

 

 

laugh

 Aug 29, 2018
 #1
avatar+21848 
+5
Best Answer

Betty goes to the store to get flour and sugar.
The amount of flour she buys, in pounds, is at least 6 pounds more than half the amount of sugar,
and is no more than twice the amount of sugar.
Find the least number of pounds of sugar that Betty could buy.

 

Let \(y\) = flour
Let \(x\) = sugar

 

\(\begin{array}{|rcll|} \hline y &\ge& 6+\dfrac x2 \\ y &\le& 2x \\ \hline \end{array}\)

 

\(\begin{array}{|rcll|} \hline && & y \ge 6+\dfrac x2 \\ && & y \le 2x \\\\ \underline{x_{\text{min}}:} \\ 2x &=& 6+\dfrac x2 \\\\ 2x-\dfrac x2 &=& 6 \\\\ \dfrac32\cdot x &=& 6 \\\\ x &=& \dfrac23 \cdot 6 \\\\ \mathbf{ x} & \mathbf{=} & \mathbf{4\ \text{pounds}} \\ \hline \end{array}\)

 

The least number of pounds of sugar that Betty could buy are \(\mathbf{4\ \text{pounds}}\).

 

 

laugh

heureka Aug 29, 2018

6 Online Users

avatar
avatar
avatar
avatar