Marina bought a total of 19 hens and ducks. She got a discount of ৳0.70 for each hen and a discount of ৳ 1.60 for each duck. She saved ৳24.10 in total. How many ducks did she buy?

Shabana drove 47.1848 km to visit her grandmother. When she reached her grandmother's house she noticed that the car had used up 3.49 liters of petrol. How many kilometers did she travel per liter of petrol?