a)

$36\underline{0}:9=4\underline{0}$  

$72\sout{0}:8\sout{0}=9$  

$160:5=\left(150+10\right):5=150:5+10:5=30+2=32$  

 

b)

$91:7=\left(70+21\right):7=70:7+21:7=10+3=13$  

$84:6=\left(60+24\right):6=60:6+24:6=10+4=14$  

$168:8=\left(160+8\right):8=160:8+8:8=20+1=21$  

 

c) 

$48\underline{00}:6=8\underline{00}$  

$21\underline{0}\sout{0}:3\sout{0}=7\underline{0}$  

$350\sout{00}:7\sout{00}=50$