for the first question
1. ( 5cm / 2km ) = ( xcm / 5km )
5*5 = 2x
25 = 2x
12,5cm = x
2. similar to (1) but having x as the km and 2 as the cm
5x = 2*2
x = 0,8 km
3. 192:2 to find the ratio of 1 cm to multiply by the length of the map
96*8.125=780cm
4. the are is (base*length)/2
use the same logic of (3) to find the real length of base
5*96=480cm
so for the the area (480*780)/2= 187200cm^2