cost of a square slab is proportional to its thickness and proportional to the square of its length , what the cost of square slab 3 meter long and 0.1 meter thick?
1. the cost 2meters long and 0.2 meters thick is 160dollars more than cost of 2 meters long and 0.1 meters thick
2. cost of 3 meters long 0.1 meter thick is 200 more than the cost of 2 meters long and 0.1 meters thick