Question

Observe the graph and calculate the y intercept for the straight line given.

• A. 46 units
• B. 56 units
• C. 66 units
• D. 76 units

Answer 1

The correct option is C 66 units

From the graph, consider the points $(10,76)$ and $(30,96)$

You know, Slope(m) = $\frac{y_2-y_1}{x_2-x_1}$
Putting values, you get
Slope (m) = $\frac{96-76}{30-10}$
= $\frac{20}{20}$
= $1$

You know, equation of a straight line is given by $y=mx+c$
∴ Subituting the value of $m=1$ in the equation, you have,
$y=x+c$ (where c is the y-intercept)

Now, putting the given point (10, 76) in the equation, you get,
$76=1\times 10+c$
$\Rightarrow 76=10+c$
$\Rightarrow c=66$

∴ Value of y-intercept will be $66$