Question

probabillity
India play two matches each with West indies andAustralia.In any match, the probabilities of india getting 0,1,and 2 points are "0.45,0.05,and 0.50"respectively.Assuming that the outcomes are independent, the probability of india getting at least 7 points is
a)0.0875 b)1/16 c)0.1125 d)none of these

Answer 1

guy's help me

Answer 2

@ParthKohli

Answer 3

help guy's

Answer 4

Lets label the events in which India plays as an opponent.
W1, W2, A1, A2

Answer 5

ok

Answer 6

how many ways can you add up to 7

Answer 7

means

Answer 8

if you are talking about to add four no. and getting 7 than i think this is only 1 way, b'cos we can only get two points in one match, so 2+2+2+1=7

Answer 9

That is correct
For exactly 8 points we have 1 case.
2 + 2 + 2 + 2
For exactly 7 points we have 4 cases.
2 + 2 + 2 + 1
2 + 2 + 1 + 2
2 + 1 + 2 + 2
1 + 2 + 2 + 2

Answer 10

now replace the cases with the probabilities

Answer 11

P( x = 8) = 0.5*0.5*0.5*0.5
PX = 7) = 4 choose 3 * 0.5^3 * 0.1^1

Answer 12

but when you calculate for seven points it also count repets that 2 are same so why we count more in 7 points

Answer 13

Am I allowed to give the answer?

Answer 14

at first you solve and give me answer than we discuss what you say

Answer 15

yes there are 4 ways you can get
2,2,2,1 points

Answer 16

so what's the answer you get

Answer 17

.1125

Answer 18

i should let you do the calculation

Answer 19

but the answer was actually in answer pellet was 0.0875

Answer 20

ah and that is

Answer 21

P ( x is at least 7 )
= P( X >= 7 )
= P(X =7 ) + P(X=8)
= (4 C 3) * 0.5^3 * 0.05^1 + 0.5^4
= 4* 0.5^3 * 0.05^1 + 0.5^4
= 0.0875

Answer 22

ah ok i got it thanks