Multiple choice

If we take $1280$ sets each of $10$ tosses of a fair coin, the number of sets we expect to get $7$ heads and $3$ tails is

  1. $450$
  2. $300$
  3. $150$
  4. $75$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The probability of getting 7 heads in 10 tosses is given by the binomial formula: 10C7 * (0.5)^10 = 120 / 1024 = 15/128. For 1280 sets, the expected number is 1280 * (15/128) = 150.

AI explanation

To find the expected number of sets with 7 heads and 3 tails, use the binomial probability formula to find the chance of getting exactly 7 heads in 10 tosses. The probability is C(10,7) times (0.5)^7 times (0.5)^3, which equals 120 divided by 1024, or 15 divided by 128. Multiplying this probability by the 1280 sets gives an expected number of 150 sets.

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