MathDB
Problems
Contests
International Contests
Tournament Of Towns
1985 Tournament Of Towns
(101) 5
(101) 5
Part of
1985 Tournament Of Towns
Problems
(1)
TOT 101 1985 Autumn J5 two throw coins.10-11 times, more heads
Source:
8/26/2019
Two people throw coins. One throws his coin
10
10
10
times, the other throws his
11
11
11
times . What is the probability that the second coin fell showing "heads" a greater number of times than the first?(For those not familiar with Probability Theory this question could have been reformulated thus : Consider various arrangements of a
21
21
21
digit number in which each digit must be a "
1
1
1
" or a "
2
2
2
" . Among all such numbers what fraction of them will have more occurrences of the digit "
2
2
2
" among the last
11
11
11
digits than among the first
10
10
10
?)(S. Fomin , Leningrad)
combinatorics
probability