Let's leave aside the question of 1.2. 3. Inverse proportion, positive proportion, 4. Solve the problem first, 100: 2 = x: 3x = 150, 60x = 50× 3x = 2.564.1.27,650. The positive scale is 4.2000000, 1cm= actual 20km20 * 5.5 =1/0km1:5000, 1cm= actual 50m = 0.05km1/. Because the number of columns is inversely proportional to the number of columns, then 25/20=X/24, that is, 20X=25*24, and the solution is X=30.