$$\left. \begin{array} { l } { 15 A = [ 37 ] } \\ { 813 = [ 214 ] } \\ { n = 120 } \\ { 50 } \\ { 50 } \end{array} \right.$$
$A=\frac{37}{15},\ \text{false},\ n=120,\ a=50,\ b=50$
