[banker]

$ \left(19\frac{4}{5} \right) \left(11\frac{1}{4} \right) = (20 - \frac{1}{5})(12 - \frac{1}{4})$

$ = 240 - 5 + \frac{1}{20} - \frac{15}{2}$

$234 +1 + \frac{1}{20} - 7 - \frac{1}{2}$

$227 +1 + \frac{1}{20} - \frac{1}{2}$

$227 + \frac{9}{20} = 227\frac{9}{20} = a\frac{b}{c}$

$a+b+c = 227+9+20 = 256 $

ตอบ ข้อ ง.



EDIT


$ = 240 - 5 + \frac{1}{20} - \frac{12}{5}$

$235 + \frac{1}{20} - 2 - \frac{2}{5}$

$232 +1 + \frac{1}{20} - \frac{2}{5} $

$232 + \frac{13}{20} = 232 \frac{13}{20} = a\frac{b}{c}$

$a+b+c = 232+13+20 = 265 $

ตอบ ข้อ ข.