Question

Please explain! (:
If we toss 3 coins 100,000 times. How many times do we expect to see "Exactly 1 Head" appearing?

A.12,500
B.37,500
C.3,750
D.50,000

Answer 1

12500

Answer 2

can you explain why?

Answer 3

is it not 37500?

P( head) = 0.5

HTT
THT
TTH
3 situations, with same probability:
3*(0.5*0.5*0.5) = 3/8

Expected = 3/8*100000 = 37500

Answer 4

(3/8)*100000

Answer 5

the probability of a head on one toss = 1/2
if we have one head on tossing 3 coins together
possibilities are
htt
tht
tth
probabilty of any of these = 3 * 1/8 = 3/8

so the answer is 3/8 * 100,000 = 37500

Answer 6

for each toss we have 8 cases
(hhh)(hht)(hth)(thh)(htt)(tht)(tth)(ttt)

3 of these have only 1 head
so the probability of obtaining only 1 head is 3/8

for 100,000 tosses
we expect to see 100000(3/8) = 37500