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A chemist is testing 6 different liquids. For each test, the
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12 Nov 2020, 10:49
12 Nov 2020, 10:49
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Question Stats:
77% (00:24) correct
22% (01:10) wrong based on 9 sessions
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A chemist is testing 6 different liquids. For each test, the chemist chooses 2 of the liquids and mixes them together. What is the least number of tests that must be done so that every possible combination of liquids is tested?
Show: :: OA
15
Re: A chemist is testing 6 different liquids. For each test, the
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17 Nov 2020, 04:56
17 Nov 2020, 04:56
1
is it 6C2= 15 !
Re: A chemist is testing 6 different liquids. For each test, the
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08 Oct 2021, 11:09
08 Oct 2021, 11:09
1
Carcass wrote:
A chemist is testing 6 different liquids. For each test, the chemist chooses 2 of the liquids and mixes them together. What is the least number of tests that must be done so that every possible combination of liquids is tested?
Show: :: OA
15
Question is pick 2 (r) from a set of 6 (n) without replacing and order does not matter. Formula is \(nC_r = 6C_2 = \frac{(6*5)}{2} =15\)
Solving without formula:
Let chemicals be A,B,C,D,E,F and the possible options are
i) with A , there are 5 options (AB, AC, AD, AE and AF)
ii) with B, there are 4 options, (BC, BD, BE and BF),
iii) with C, there are 3 options, (CD, DE and CF)
iv) with D, there are 2 options, (DE and DF)
v) with E, there is 1 option (EF)
So 1+2+3+4+5 = 15
