Elitmus
Exam
Numerical Ability
Probability
53.On a toss of two dice .A throws a total of 5.Find the probability that he thros another 5 before throws 7
Read Solution (Total 9)
-
- probability to get 5
(1,4)
(4,1)
(2,3)
(3,2)
probability to get 7
(1,6)
(6,1)
(2,5)
(5,2)
(3,4)
(4,3)
SO,
total possibility is n(S)=6+4=10.
to get 5 si n(E)=4
probability to get five before 7 is=n(E)/n(S)=>4/10
=>.4 is the right answer.
- 10 years agoHelpfull: Yes(28) No(3)
- @Rajnish bhai tu upar se sikh ke aaya thha kya english..
- 10 years agoHelpfull: Yes(18) No(0)
- bhai who ever u r....first correct ur english...else dont post....
- 10 years agoHelpfull: Yes(11) No(8)
- Its so difficult here to interpret the question when people are so bad at their usage of english! Please post question only when you are sure of the sentences framed by you .
- 9 years agoHelpfull: Yes(4) No(4)
- to get 5
(1,4)
(2,3)
(3,2)
(4,1)
there is a chance of to get 6 before throws 7
(3,3)
(4,2)
(5,1)
(2,4)
(1,5)
Therefore probability is 9/36=1/4
- 10 years agoHelpfull: Yes(3) No(8)
- table for two throws
2 3 4 5 6 7
3 4 5 6 7 8
4 5 6 7 8 9
5 6 7 8 9 10
6 7 8 9 10 11
7 8 9 10 11 12
p(5)=4/36
p(7)=6/36
p(total exept 5 and 7)=26/36
p(5 before 7)=4/36*6/36 +26/36*4/36*6/36+.......................=ans
- 10 years agoHelpfull: Yes(2) No(3)
- W−−−−−−−−>∙∙====> swimmer.
In the first leg she swam 50m50m, so in the 2nd leg she must have swum 100m100m
In the 2nd leg, she swam L−50+30,L−50+30, so equating
L−50+30=100L−50+30=100, which yields L=120m - 8 years agoHelpfull: Yes(0) No(1)
- And is 2/5 since 5 can be throw in 4 ways so prob is 4/36 or we can say 1/9 similarly for 7 can be throw in 6 ways so probability is 6/36 or 1/6 .neither 5 nor 7 in 26 ways so probability is 26/36 or 13/18 .........prob that ist throw we get 5 + probability that 2 time throw and at 2 nd time we get 5 before that we don't get 5 and 7 +..... Thus forms and infinite gp so 1/9+13/18*1/9+13/18*13/18*1/9+........ So we get 2/5
- 7 years agoHelpfull: Yes(0) No(0)
- In question given, son age difference should be 1 then,
1*2*3*4=24=25-1
2*3*4*5=120=121-1(mean suare-1 is possible because in this if we take primeno+1 than it will not possible becoz 119+1 but 119 is not prime no).
3*4*5*6=360=361-1 - 6 years agoHelpfull: Yes(0) No(0)
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