COIN TOSS ODDS
Fair coin • choose tosses + event • get probability
Uses combinations • NO SCROLL
TOSSES (n)
6
Max 12 to keep it readable
EVENT
EXACT
Heads count out of n tosses
k (HEADS)
3
Clamped to 0..n
ROUNDING
2DP
% rounding only
TIP
2^n
Total outcomes = 2^n
Fair coin: p=1/2
DISPLAY
FRAC
Answer shows fraction + %
Working uses nCk
WORKING
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PROBABILITY
READY
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TOSSES (n)
6
Max 12
EVENT
EXACT
Heads out of n
k (HEADS)
3
Clamped to 0..n
ROUNDING
2DP
% rounding only
WORKING
—
—
—
—
—
PROBABILITY
READY
—
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KEY IDEA
Total outcomes = 2^n
Each sequence is equally likely
P = favourable ÷ total
EXACTLY k HEADS
P = nCk / 2^n
nCk counts arrangements
of k heads in n tosses
AT LEAST / AT MOST
Add exact probabilities
P(≥k)= Σ(nCr)/2^n
P(≤k)= Σ(nCr)/2^n
WORKED EXAMPLE
n=6, exactly k=3
6C3 = 20
P = 20/64 = 31.25%
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