20 БАЛЛОВ (1целая 2\3-3\8):2целых 2\5

(1[latex] \frac{2}{3} [/latex] - [latex] \frac{3}{8} [/latex]) : 2[latex] \frac{2}{5} [/latex] = ([latex] \frac{5}{3} [/latex] - [latex] \frac{3}{8} [/latex]) : [latex] \frac{12}{5} [/latex] =  ([latex] \frac{40}{24} [/latex] - [latex] \frac{9}{24} [/latex]) : [latex] \frac{12}{5} [/latex] = [latex] \frac{31}{24} [/latex] : [latex] \frac{12}{5} [/latex] = [latex] \frac{31}{24} [/latex] * [latex] \frac{5}{12} [/latex] = [latex] \frac{155}{288} [/latex]