May 24, 2013
special question of part A
Q-In a bag containing only blue , red & green marbels all but 15 are blue , all but 13 are red & all but 12 are green . How many are red ?
(a) 13
(b) 7
(c) 25
(d) 20
Q-A coin is tossed 6 times . the probability that heads will occur at least once is ?
(1) 63/64
(2) 1/3
(3) 1/64
(4) 3/2
how that r-b came? pls explain that and also post some more tricks to solve this type of questions if you know ...
plz post some more questions apart from the model questions given by csir. thnx for starting dis forum..cud b quite useful
Q-In a bag containing only blue , red & green marbels all but 15 are blue , all but 13 are red & all but 12 are green . How many are red ?
(a) 13
(b) 7
(c) 25
(d) 20
Q-A coin is tossed 6 times . the probability that heads will occur at least once is ?
(1) 63/64
(2) 1/3
(3) 1/64
(4) 3/2
(a), (3). Thanks
i think ur ans is correct . can u explain plz how these equations are solved of ball questions.
sorry friends . the correct ans of these questions actualy i don't know .these questions are asked in sampel paper of new revised syllabus of part A downloaded by csir .
pls post ans too
thank u
1 & 3
-A coin is tossed 6 times
1st time (H.T) so probability of head 1/2
2nd time (H,T) so probability of head 1/2
3rd time....................................................1/2
4th time.....................................................1/2
5th time.......................................................1/2
6th time .......................................................1/2
so probability of head atleast once ...1/2*1/2*1/2*1/2*1/2*1/2=1/64
ans 3
allk but means not
all but 15 are blue means 15 are not blue .so it may be red+green=15
blue+green=13
blue+red=12
r+g=15
b+g=13
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r-b=2
r+b=12 .so 2R=14 r=7.like wise calculate remaining