A car can travel 45 km in 5 liters of petrol how for would it travel in 12 liters of petrol

Answer 1

5 litres will take you 45 km
1 litre will take you 9 km
so, 12 litres will take you 108 km

or , just use a simple proportion:
5/45 = 12/x
5x = 540
x = 540/5 = 108

Answer 2

45/5 = 9 km per liter

12 * 9 = _______ km

Answer 3

If 30 dozens of eggs cost BD 50. Find the cost of 5-dozens of eggs?