A box contains 4 red, 6 blue, 5 green pens. What is the probability that the pen picked up
is :
a) Blue b) Red c) Not blue
Answers
Answer:
a, 0.4 ( 6/15 )
b, 0.26 ( 4/15 )
c, 0.6 ( 3/5 )
Step-by-step explanation:
Total number of balls = 4 + 6 + 5 = 15
Probability of getting a blue ball = Number of blue balls / Total number of balls
A, Probability of getting a blue ball = 6 / 15 = 0.4
Probability of getting a red ball = Number of red balls / Total number of balls
B, Probability of getting a blue ball = 4 / 15 = 0.26
Probability of getting a blue ball = ( Number of blue green + Number of red balls) / Total number of balls
C, Probability of getting a blue ball = 9 / 15 = 3 / 5 = 0.6
Step-by-step explanation:
let S be the sample space.
S={R1,R2,R3,R4,B1, B2,B3,B4,B5,B6,G1,G2,G3,G4,G5}
n(S)=15
let A be the event of getting the pen picked up is blue.
A={B1, B2,B3,B4,B5,B6}
n(A)=6
n(P)=n(A)/n(S)
=6/15
=2/5
let B be the event of getting the pen picked up is red
B={R1,R2,R3,R4}
n(B)=4
n(P)=n(B)/n(S)
=4/15
let C be the event of getting the pen picked up is not blue.
C={R1,R2,R3,R4,G1,G2,G3,G4,G5}
n(C)=9
n(P)=n(C)/n(S)
=9/15
=3/5