getting exactly three correct answers if you guess the answers at random.
***The answer is 9%. Anyone know how you arrive at 9%?
2006-08-18 11:07:45 · 6 answers · asked by Linduh. 3 in Science & Mathematics ➔ Mathematics
Each question can be answered in 4 ways.
So, Total number of ways to answer = 4 ^5 = 1024
Now, with 3 correct answers, first choose 3 questions out of 5 randomly in 5C3 ways = 10 ways.
Now other 2 questions can be answered in 3 ways each.
So, number of ways to get exactly 3 correct answers = 10 x 9 = 90 ways
So, probability = 90/ 1024 = 8.78%
Your answer of 9% is rounded off.
2006-08-18 11:24:14 · answer #1 · answered by DG 3 · 1⤊ 0⤋
5+4=9
?
2006-08-18 11:15:59 · answer #2 · answered by Anonymous · 0⤊ 1⤋
i got 8% by saying there is 25% for getting the answer right, so three answers is .25 x .25 x .25 = .015625, multiply by 5 since there are five possible answers and u get 8%. im just guessing bc i dont really remeber, and obviously i didnt get the right answer.
2006-08-18 11:24:39 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Throwing 9 dices at one time, you should get 9% of the correct answer!!!
2006-08-18 11:20:41 · answer #4 · answered by lonelyspirit 5 · 0⤊ 0⤋
Out of five question you want exactly three questions right.There are 20 answers in all out of which you need 3 question right
5C3/20C3=10/1140=0.008771929
The percentage will be =0.008771929=0.877192982=0.9%
2006-08-18 11:27:55 · answer #5 · answered by Amar Soni 7 · 0⤊ 0⤋
ummmmm no?
2006-08-18 11:14:14 · answer #6 · answered by Anonymous · 0⤊ 1⤋