Question

Observe the graph given below:
where,
y - Number of vaccines
x - Days


Find on which day will the vaccine production meet the vaccine requirement?

• A. 3
• B. 4
• C. 4.5
• D. 5

Answer 1

The correct option is B 4

General form of equation is given as $y=mx+c$
For the straight line for "Vaccine Produced"
Consider points (2, 3) and (1, 2).


$Unitrate=slope\left(m\right)=\frac{changeiny}{changeinx}=\frac{y_2-y_1}{x_2-x_1}$

By putting values, you get slope(m)
$=\frac{3-2}{2-1}=1$
and y-intercept = 1

∴ Equation of line for vaccine produced $isy=x+1$

For the straight line for "Vaccine Needed"
Consider points (3, 3) and (2, 1).


$\therefore slope=\frac{changeiny}{changeinx}=\frac{y_2-y_1}{x_2-x_1}=\frac{3-1}{3-2}=2$
and y-intercept = -3

∴ Equation of line for vaccine produced $isy=2x-3$

On solving the equations,
$wegetx+1=2x-3$
$\Rightarrow x-2x=-3-1$ [ By changing the sides]
$\Rightarrow -x=-4$
$or,x=4days$

∴ It takes 4 days to meet the vaccine requirement with the given production capacity.