решите пожалуйста. задание во вложениях!!!

В 40 л воды растворили 1,5 кг соли.Определите концентрацию полученого раствора (ответ округлите до десятых ). 

ЗАРАНИЕ ОГРОМНОЕ СПАСИБО !!!

(2 целых 3/25+9,6-5,72)делить на 0,15=

10,92 делить(2,6 умножить на 0,5)-0,4

Масса слонёнка составляет 1/6 массы слонихи. Сколько весит слонёнок, если масса слонихи 4т8ц.

Помогите вставить слова в текст, за место многоточий...

Слова, которые нужно вставить: achieve, available, borrow , fluent, major, native, practice, rank, recognize, throughout, widespread.

Текст: 

Russian, also called Great Russian, is a member of the Indo-European family of languages. As Russian is a ........ language, it is considered to be one of the ........ world languages. Knowlidge of the Russian language opens the door to the study of Russia's rich tradition of literature, art and music. Russian literature ......... among the most beautiful and exciting national literatures in the world. Russian is the .......... language of the greatest people known ........ the world: L. Tolstoy, P. Tchaikovsky, I. Pavlov, A. Sakharov, to name just a few. Russian ............ as a very difficult language. If you speak Italian, French or German, you will learn Russian vocabulary even more easily as many words ........ in the 18th and 19 th centuries from these languages.
If you neither travel regulary to Russia nor have a Russian pen friend, you should ........ your Russian in other ways. There is a wealth of books and DVDs waiting for you, and many are ...... at local Russian shops. If you study Russian one hour a day regularly, you will probably be in three years. Being able to read a newspaper artice with a dictionary can be .... in a year.