Final answer:
To find the number of litres of petrol required to cover 70 km, set up a proportion using the given information and solve for the unknown variable.
Step-by-step explanation:
To find the number of litres of petrol required to cover 70 km, we can set up a proportion using the given information. We know that the car can cover 210 km using 15 litres of petrol, so we can set up the proportion:
210 km / 15 L = 70 km / x L
Cross multiplying, we get:
210x = 70 * 15
Simplifying, we find:
x = (70 * 15) / 210
Calculating, we find that x = 5. Therefore, the car will require 5 litres of petrol to cover 70 km.