The taxi charges in a city comprise of a fixed charge, together with the charge of the distance covered. For a journey of 16 km, the charges paid are $156 and for a journey of 24 km, the charges paid are $204. What will a person have to pay for travelling a distance of 30 km?
$236
$240
$248
$252
Correct answer is B
Let the fixed charge be $x and variable charge be $y per km. Then,
x + 16y = 156 ...(i) and
x + 24y = 204 ...(ii)
Solving (i) and (ii), we get: x = 60, y = 6.
Therefore Cost of travelling 30 km = 60 + 30 y = $(60 + 30 x 6) = $240.