冷面画皮的回答：

解：设大书包进价为x元，则小书包进价为（x-10）元，依题意，得：    | 【解析】 30％（x-10）=20％x                                                                              |两种书包的所获利润相同，而小书             0.3x-3=0.2x                                                                                |包利润率是30％，大书包利润率是         0.3x-0.2x=3                                                                                    |20％。因而得知：大书包进价的                 0.1x=3                                                                                    |20％=小书包进价的30％，得出方                      x=30                                                                                  |程：30％（x-10）=20％x。 小书包：x-10=30-10=20                                                                         | 答：大书包进价为30元，小书包进价为20元。                                        | 【公式】利润=利润率×进价