30 дециметров -12дециметров 5сантиметров=?

17 дм 5 см это правильный ответ  я сам решал                                                    

The cook Islands consist of 15 small Islands and atolls with a total area of 240 square kilometers. They are located to the North-East of New Zealand, their neighbours on the water border are American Samoa, Niue, Kiribati and French Polynesia.
  
The cook Islands are divided into two groups: North and South. Rarotonga (part of the southern group) is the most populous island and has the largest area. On the North coast of the island is the capital of the whole archipelago Kurskogo — "the city of two harbors" Avarua.

Cook Islands are in free Confederation with New Zealand, i.e. they preserve their independence and sovereignty, but many of the functions of government assigned to a large state.

Dominant role in the economy of the Islands is given over to tourism, agriculture and financial sector.

Cook Islands got its name in honor of the English Explorer James cook, and named the archipelago the least well-known Explorer, our compatriot, Ivan Fedorovich Kruzenshtern.

By the way, about James Cook. Despite the current and firmly settled in people's minds the view that English traveler ate the natives of the cook Islands, this is not true. Cook was killed in Hawaii. Visiting the cook Islands, You will be able to personally refute this version of fate of an Englishman. Here you will meet cheerful and good-natured people!

I always use summer holidays for some easy work on the subjectsthat I need for my future studies. I improve my English, read literature and some historical materials. This work brings benefit and pleasure: reading books and listening to English songs, watching documentaries and training your memory while memorizing some verses, English phrases or dates. I am glad that my mother has taught me to do it easily and without any nervous tension. If you treat this work as a game or an amusement you can enjoy a part of the summer and facilitate for your future busy learning season.