M4maths Previous Puzzles

20 Dec 2012 jeweller

How many words can be formed by using all the letters of the word JEWELLER, if W and J are respectively the first and last letters of the words formed

OPtion

1) 24
2) 60
3) 96
4) 120
5) 720
6) 780
7) 900
8) 960
9) 1920
10) none of these

Solution

since first and last letters are fixed so no. of methods to arrange other 6 letters = 6*5*4*3*2*1/3*2*1*2*1 = 60

Correct Option: 2 Best Solution (0)

19 Dec 2012 probability

The probability of passing an exam by A is 0.2 and the same by B is 0.3; What will be the probability that only one of them could pass the exam.

OPtion

1) .14
2) .21
3) .24
4) .38
5) .06
6) .56
7) .68
8) .54
9) .76
10) none of these

Solution

required probability = 0.2*0.7 + 0.3*0.8 = 0.14+.24 = 0.38

Correct Option: 4 Best Solution (0)

18 Dec 2012 real root

Total no. of real roots of the equation
3x^4+4x^3+5x+1=0 are

OPtion

1) 0
2) 1
3) 2
4) 3
5) 4
6) 5
7) none of these

Solution

In 3x^4+4x^3+5x+1 no sign change so no. of positive roots = 0
now put -x in the place of x, we get
3x^4-4x^3-5x+1, this equation has sign change twice so no. of negative roots = 2
so total real roots = 0+2 = 2

Correct Option: 3 Best Solution (0)

17 Dec 2012 sequence

7,11,18,22,?,33
? will be

OPtion

1) 23
2) 24
3) 25
4) 26
5) 27
6) 28
7) 29
8) 30
9) 31
10) none of these

Solution

11-7 = 4
22-18 = 4
33-? = 4
so ? = 29

Correct Option: 7 Best Solution (0)

14 Dec 2012 inequation

a+b+c>=d
If a is the root of 4x+1=0 and b,c are the roots of 4x^2+3x+k=0, then greatest value of d will be

OPtion

1) 1
2) -1
3) 2
4) -3/4
5) -3
6) -4/3
7) 4
8) 3/2
9) -3/2
10) none of these

Solution

according to the given conditions a = -1/4
and b+c = -3/4
so a+b+c = -1
so greatest value of d = -1

Correct Option: 2 Best Solution (0)

13 Dec 2012 golu and kaku

Golu and kaku are brothers. Sum of their ages is equal to 1/3 of the age of their mother.The difference of ages of the 2 brothers is 4 years and the sum of ages of their mother and father is 66, then possible no. of ages of mother will be
Given that the age of father is more than the age of mother and at the time of marriage age of mother was 25

OPtion

1) 1
2) 2
3) 3
4) 4
5) 5
6) 6
7) 7
8) 8
9) 9
10) none of these

Solution

according to the given condition
k+g = m/3,
g-k = 4
f+m = 66
and f>m
on solving these conditions we will get
m = 3(2k+4) and f+m = 66
on putting k = 1, m = 18
k = 2, m = 24
k = 3, m = 30
k = 4, m = 36
only m = 30 and k = 3 may be a possible case but if k = 3 so g = 7 and age of marriage = 25 so data are inappropriate
so no solution is acceptable

Correct Option: 10 Best Solution (0)

12 Dec 2012 series

a+(a/2)+(a/4)+(a/8)+(a/16)+................upto infinite = 40
then a will be

OPtion

1) 20
2) 15
3) 12
4) 10
5) 9
6) 21
7) 25
8) 28
9) 18
10) none of these

Solution

a+(a/2)+(a/4)+(a/8)+(a/16)+................upto infinite
by using formula of sum of infinite terms we get 2a
so 2a = 40, a = 20

Correct Option: 1 Best Solution (0)

11 Dec 2012 probability

There are two sets A = {1,2,3,4} and B = {3,4,5,6}. We have to select 1 number from A and 1 number from B. Probability to get the condition in which number selected from A is greater than the number selected from B.

OPtion

1) 1
2) 1/4
3) 1/8
4 3/8
5) 1/16
6) 3/16
7) 7/16
8) 7/8
9) 1/2
10) none of these

Solution

only 4,3 is favorable case

Correct Option: 5 Best Solution (0)

10 Dec 2012 sequence

x,11,1,y,0,13,.....................
sum of x and y will be

OPtion

1) 10
2) 12
3) 13
4) 14
5) 16
6) 18
7) 19
8) 20
9) 21
10) none of these

Solution

according to the given sequence
x = 2
and y = 12
so x+y = 14

Correct Option: 4 Best Solution (0)

07 Dec 2012 remainder

On dividing 17^17 by 4^2, remainder will be

OPtion

1) 5
2) 7
3) 9
4) 1
5) 8
6) 3
7) 2
8) 6
9) 4
10) none of these

Solution

17^17 = (1+16)^17 = 1+factor of 16
on dividing it by 16 remainder will be 1

Correct Option: 4 Best Solution (0)