va rog frumos ex 8 a,c,d,e urgent

A) 3m/15cm
15cm=0,15
=> 3/0,15=20
B) 3h/45min
45 min= 3/4
3/3/4=3/0,75=4
C)7,5 kg/250g
250g=0,25kg
7,5/0,25=30
D) mai=31
August=30
31+30=61
E) 999;99