Probability 3 Question 25

25. If E¯ and F¯ are the complementary events of E and F respectively and if 0<P(F)<1, then

(1998,2M)

(a) P(E/F)+P(E¯/F)=1

(c) P(E¯/F)+P(E/F¯)=1

(b) P(E/F)+P(E/F¯)=1

(d) P(E/F¯)+P(E¯/F¯)=1

Show Answer

Solution:

  1. (a) P(E/F)+P(E¯/F)=P(EF)P(F)+P(E¯F)P(F)

=P(EF)+P(E¯F)P(F)=P(F)P(F)=1

Therefore, option (a) is correct.

(b) P(E/F)+P(E/F¯)=P(EF)P(F)+P(EF¯)P(F¯)

=P(EF)P(F)+P(EF¯)1P(F)1

Therefore, option (b) is not correct.

(c) P(E¯/F)+P(E/F¯)=P(E¯F)P(F)+P(EF¯)P(F¯)

=P(E¯F)P(F)+P(EF¯)1P(F)1

Therefore, option (c) is not correct.

(d) P(E/F¯)+P(E¯/F¯)=P(EF¯)P(F¯)+P(E¯F¯)P(F¯)

=P(EF¯)+P(E¯F¯)P(F¯)=P(F¯)P(F¯)=1

Therefore, option (d) is correct.



जेईई के लिए मॉक टेस्ट

एनसीईआरटी अध्याय वीडियो समाधान

दोहरा फलक