The car hire charges in a city computerise of a fixed charges together with the charge for the distance covered. For a journey of 12 km, the charge paid is Rs 89 and for a journey of 20 km, the charge paid is Rs 145. What will a person have to pay for travelling a distance of 30 km?

Let the fixed charge be ‘a’ and the charge per km travelled be ‘b’


Given, for a journey of 12 km, the charge paid is Rs 89 and for a journey of 20 km, the charge paid is Rs 145


⇒ a + 12b = 89 ----- (1)


a + 20b = 145 ----- (2)


(1) – (2)


⇒ 8b = 56


⇒ b = 7


Thus, a + 84 = 89


⇒ a = Rs. 5


For a distance of 30km, amount paid = 30 × 7 + 5 = Rs. 215


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