Question

Price of one Pound (in $)	$1.20$	$1.40$	$1.60$	$1.80$	$2.00$	$2.20$
Quantity sold (in Pounds)	$15,000$	$12,500$	$10,000$	$7,500$	$5,000$	$2,500$

The linear relationship between $g$, number of pounds of grain sold, and $d$, price in dollars of one pound of grain, is represented by

• A. $g=1.2d+12,500$
• B. $g=12,500d+15,000$
• C. $g=-12,500d+17,500$
• D. $g=-12,500d+30,000$

Answer 1

The correct option is D $g=-12,500d+30,000$

The following straight line passes through $(1.2,15000)$ and $(1.4,12500)$.

Hence, the equation of the straight line is given by $\frac{g-15000}{d-1.2}=\frac{g-12500}{d-1.4}$

$\Rightarrow -1.4g-15000d+21000=-12500d-1.2g+15000$

$\Rightarrow 0.2g=6000-2500d$

$\Rightarrow \frac{g}{5}=-2500d+6000$

$\Rightarrow g=-12500d+30000$