Math Is Fun Forum
Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °
You are not logged in.
- Topics: Active | Unanswered
Pages: 1
#1 2006-03-13 11:19:01
- 4littlepiggiesmom
- Member
- Registered: 2006-01-09
- Posts: 42
2 probablility questions
1. Suppose a fair coin is tossed 7 times. How many ways are there to get exactly three heads or three tails? I got B
Answer choices-
a. 7
b. 21
c. 35
d. 210
e. None of theese
2. Suppose three fair dice are thrown. What is the probabliity that the top faces will sum to 6?
a. 1
b. 1/6
c. 1/216
d. 5/108 MY ANSWER
e. Non of the these
Am I getting the right answer or do I need to redo it...again? K
Offline
#2 2006-03-13 15:27:48
- George,Y
- Member
- Registered: 2006-03-12
- Posts: 1,379
Re: 2 probablility questions
c: 7 6 5/(3 2 1)=35
d: right (diceA diceB diceC) = (1 1 4), (1 4 1), (4 1 1), (1 2 3), (1 3 2), (2 1 3), (2 3 1), (3 1 2), (3 2 1), (2 2 2) ;Prob=(3+6+1)/(6 6 6)
Last edited by George,Y (2006-03-13 15:28:12)
X'(y-Xβ)=0
Offline
#3 2006-03-13 16:46:56
- 4littlepiggiesmom
- Member
- Registered: 2006-01-09
- Posts: 42
Re: 2 probablility questions
Thanks so much~
Offline
#4 2006-03-13 17:01:52
- George,Y
- Member
- Registered: 2006-03-12
- Posts: 1,379
Re: 2 probablility questions
You r welcome
X'(y-Xβ)=0
Offline
Pages: 1