Eric,Betty,Tracy and Jack sit randomly at a square table. What is the probability that Eric sits opposite to Tracy?
A 1/3
B 1/6
C 1/8
D 1/12
l want clear step...
thx..
maths MC
2007-10-11 2:51 am
回答 (3)
2007-10-11 3:00 am
✔ 最佳答案
Probability for Eric to sits opposite to Tracy = 4 X [1/4 X (1/3)]
= 1/3
So, the answer is A
It is because there are 4 choices for Eric to choose a seat.
Once Eric has chosen a seat, Tracy will have 1/3 chance to choose a seat opposite to Eric.
參考: Myself~~~
2007-10-11 3:06 am
Probability for Eric to sits opposite to Tracy
= 4 X [1/4 X (1/3)]
= 1/3
So, the answer is A
It is because there are 4 choices for Eric to choose a seat.
Once Eric has chosen a seat, Tracy will have 1/3 chance to choose a seat opposite to Eric.
Assume that Eric sit in Seat 1, tracy must sit in Seat 3
so the answer is 1/4*1/3*2*2=1/3
*2 means they can change the seat and sit in seat2 and seat4
= 4 X [1/4 X (1/3)]
= 1/3
So, the answer is A
It is because there are 4 choices for Eric to choose a seat.
Once Eric has chosen a seat, Tracy will have 1/3 chance to choose a seat opposite to Eric.
Assume that Eric sit in Seat 1, tracy must sit in Seat 3
so the answer is 1/4*1/3*2*2=1/3
*2 means they can change the seat and sit in seat2 and seat4
參考: me,me,me
2007-10-11 3:03 am
Assume that Eric sit in Seat 1, tracy must sit in Seat 3
so the answer is 1/4*1/3*2*2=1/3
*2 means they can change the seat and sit in seat2 and seat4
so the answer is 1/4*1/3*2*2=1/3
*2 means they can change the seat and sit in seat2 and seat4
參考: me
收錄日期: 2021-04-30 20:58:59
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