30abc : abc = 241
=> ( 30000 + abc ) : abc = 241
=> 30000 : abc + 1 = 241
=> 30000 : abc = 240
=> abc = 30000 : 240
=> abc = 125
Vậy số abc là : 125
30abc : abc = 241
( 30000 + abc ) : abc = 241
30000 : abc + abc : abc = 241
30000 : abc + 1 = 241
30000 : abc = 241 - 1
30000 : abc = 240
abc = 30000 : 240
abc = 125