Bunuel wrote:
A drawer contains red socks, black socks, and white socks. What is the least number of socks that must randomly be taken out of the drawer to be sure of having four pairs of socks? (A pair is two socks of the same color.)
A. 8
B. 10
C. 12
D. 14
E. 16
A good Q, which becomes easy the moment we understand the logic behind it...
4 pair of socks means there will be atleast two pairs of one colour..since the Q uses words"to be sure", we take the worst case where we pick a different colour each time we pick..
the worst case would be we have 3 of each colour, such that the one picked up after that fulfills the condition of four pair...
3 of each colour means 1 pair +1 of each colour..
so total =3*3=9..
now the tenth we pick, irrespective of the colour picked, would make it four pairs..
so total =9+1=10 ..
B
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