C1+2.C2+3.C3+…….+n.Cn =
n.2n
n.2n-1
(n+1)2n
(n+1)2n-1
The distance of the point (1,2) from the common chord of the circles x2+y2-2x-6y-6=0 and x2+y2+6x-16=0 is
1
1/5
5
2
5 digit numbers can be formed from the digits 0, 2,2,4,5. One number is selected at random.the probability that it is divisible by 5 is
7/16
1/16 1/16 1/26 7/26 1/16 1/26 7/26
1/26
7/26
The letters of the word SUCCESS are arranged in a row at random. The probability that all S’s come together is
3/35
1/7
3/7
The numbers 1, 2, 3... n are arranged in a random order. The probability that the digits 1, 2, 3,..., k(k
1/n!
k!/n!
(n-k)!/n!
(n-k+1)!/ n!
If the probability for A to fail in one exam is 0.2 and that of B is 0.3, then the probability that either A or B fails is
0.14
0.6
0.44
0.24
Five digit numbers can be formed from the digits 1,2,3,4,5. If one number is selected at random, the probability that it is an even number is
4/7
2/5
1/16
One number is selected at random from 1 to 100. The probability that it is a prime number is
1/4
-1/4
1/8
5/14
3 horses A, B and C run a race. If the probability of A’s win is twice that of B and the probability of B’s win is thrice that of C then the probabilities of their winning are
6/10, 3/10,1/10
4/7,2/,1/7
5/10,2/10,3/10
none
A bag contains 3 red, 4 white and 5 black balls. One ball is drawn at random. If a,b,c are the probabilities of drawing a red a white, a black ball from the bag then the ascending order of a,b,c is
a,b,c
b,c,a
c,a,b
b,a,c
In a class there are 60 boys and 20 girls. In it, half of the boys and half of the girls know cricket. The probability of a person selected from the class is either a boy or a person who knows ticket is
7/8
8/7
5/7
7/5
At a selection, the probability of selection of A is 1/7 and that of B is 1/5.The probability that both of them would not be selected is
12/35
16/35
24/35
32/35
Three students A,B,C are to take part in a swimming competition. The probabilities of A ‘s winning or the probability of B’s winning of B’s winning is 3 times the probability of C’s winning. The probability of the event of either B or C to win is
2/7
Urn A contains 6 red and 4 black balls and urn B contains 4 red and 6 black balls. One ball is drawn at random from urn A and placed in urn B. Then one ball is drawn at random from urn B and placed in urn A. if one ball is now drawn from urn A, the probability that it is found to be red is
32/55
33/55
32/63
25/66
If one ticket is randomly selected from, tickets numbered from 1to 30 then the probabilitythat the numbered on the tickets i a multiple of 5 or 7 is
1/3
2/3
4/3
5/3
In a town 40% people red Enadu, 25% people read jyothi and 15% people read both. A person is chosen at random from the town. The probability that the person chosen read Enadu but not read jyothi is
1/10
The tangents at (at12, 2at1) and (at22, 2at2) on the parabola y2=4ax are at right angles then
t1t2=-1
t1t2=1
t1t2=2
t1t2=-2
If a number x is selected from natural numbers 1 to 100,then the probability for x+100/x >29 is
41/50
47/50
39/50
37/50
Four tickets marked 00,01,11 respectively are placed in a bag. A ticket is drawn at random 5 times being replaced each time. The probability that the sum of the numbers on the tickets is 22 is
25/256
231/256
0
If P (A) =0.4, P (B) =0.5, P(C) =0.6, P (A∩B) =0.2, P (B∩C) =0.3, P (C∩A) =0.25, P (A∩B∩C) =0.1then P (AUBUC) =
0.1
0.9
0.85
0.8
Bag A contains 2 red, 3 black balls. Bag B contains 3 red, 2 black balls. One ball is drawn from the bag A and placed in B. One ball is drawn from bag B and placed in A. The probability that the composition of balls in the bags unaltered is
3/14
17/30
13/30
20/39
A bag contains2whit, 3 black and 4greenballs. If2 balls are drawn from it, one after another then the probability that the first one is white and the second one is black is
1/11
1/12
1/13
Card is drawn at random from a pocket of 100 cards numbered 1to 100. The probability of drawing a number which is a square is
1/100
2/100
3/10
In a class of 125 students 70 passed in Mathematics and 55 in statistics and 30 in both. The probability that a student, selected at random from the class, has passed in only one subject is
13/25
3/25
17/25
8/25
A, B, Care 3 news papers published from a city.20%of the population read A,16% read B,14% read C, 8% both A and C, 4% B and C,and2% read all the three. The percentage of then population who read at least one paper is
25%
30%
35%
40%
A student appears for test I,II and III. The student is successful if he passes either in tests I and II or III. The students passing in tests I,II and III are p, q and 1/2respectively.Ifthe probability that the student is successful is 1/2 then
p=q=1
p=q=1/2
p=1,q=0
A bag contains 4 tickets numbered 1,2,3,4and another bag contains 6 tickets numbered 2,4,6,7,8,9. One bag is chosen and a ticket is drawn. The probability that the ticket bears the number 4 is
1/48
5/24
A lot contains 20 articles. The probability that the lot contains exactly two defective articles is 0.4 and the probability that it contains exactly 3 defective articles is 0.6. Articles are drawn from the lot at random one by one, without replacement and tested till all defective articles are found. The probability that the testing procedure ends at the 12th testing is
11/1900
44/1900
66/1900
99/1900
If a,b, c are the probabilities of getting the sums 6,7,10 when 2 dice are thrown when the descending order of a,b,c is
If the tangents to the parabola y2=4ax at (x1,y1) and (x2,y2) meet on the axis then
x1=-x2
x1=2x2
y1=y2
y1=-y2