Question

The graph shows the cost of some taxi journeys. work out a formula for C in terms of n.

Answer 1

Given:

The graph of cost of taxi with respect to number of miles.

To find:

The formula for C in terms of n.

Solution:

In the given graph x axis represents the number of miles (n) and y-axis represents the cost of taxi (C).

From the given graph it is clear that, the line passes through the points (0,3) and (5,6). So, the equation of line is

$y-y_1=\dfrac{y_2-y_1}{x_2-x_1}(x-x_1)$

$y-3=\dfrac{6-3}{5-0}(x-0)$

$y-3=\dfrac{3}{5}(x)$

Adding 3 on both sides, we get

$y=\dfrac{3}{5}x+3$

Putting y=C and x=n, we get

$C=\dfrac{3}{5}n+3$

Therefore, the required formula is $C=\dfrac{3}{5}n+3$.