Vietnam attended the International Kolkata Book Fair opening ceremony of the 40th

International Book Fair 40th Kolkata took place on 25/1 in the city of Kolkata, West Bengal state of India, with the participation of many publishers, authors from over many countries around the world and many people claim. The most notable point is this year, Vietnam to attend the said Book Fair as the guest of honor. Kolkata Book Fair is one of the three largest annual book fair in the world. The fair this year will last until 02/07/2015, is expected to attract millions of visitors and buy books. Kolkata is also the largest cultural center of India.

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100%-95%=5%

Trong 20 kg nước biển có lượng nước là : 95% x 20 kg = 19,0 kg

Lượng muối là : 1kg

1kg tương ứng 2%

Vậy 100% là 50 kg

Lượng nước thêm vào là : 50 -19 = 31 kg

Đáp số : 31 kg