Имеется 100 образцов, из которых 30 соли, 40 щелочи и 30 кислоты. найти вероятность того, что в выборке из 10 образцов 3 соли, 4 щелочи и 3 кислоты

(0) I write I etters to I aura every month. 1.1) A
(1)T write letters to Laura very often, 1,1) A
(2)I wrote a letter to Laura yesterday. 2.1) E
(3)1 am writing a letter to Laura now. 1,2) A
(4)1 will write a letter to Laura tomorrow. З.1)В
(5)1 am going to write a letter lo Laura on Sunday, 3,3) D
(6)1 am writing a letter to Laura in the evening, 3.2) A
(7)1 have written a letter to Laura for half an hour yesterday. 2.3) E
(8)1 have written two letters to Laura this week, 2.3)b)E
(9)1 have written letters to Laura since 2004. 1.3) A
(10) 1 have written a lot of letters to Laura. 2.3) a) E

I have been to London, England.
I was there two years ago.
I stayed in a hotel.
I travelled with my family.
I visited a lot of interesting places there.
I saw Tower of London and Westminster Abbey and went to the
British Museum.
My favourite sight is Buckingham Palace.
I like it because it is very beautiful and it has a lot interesting
traditions.
I had a good time in London.
The best day of the trip was when T rode on London Eye.
My favourite souvenir is a cup of London sights.
I bought it at the exhibition.
I'm going to visit this city once more.
I think I'11 have good impressions.