M4maths Previous Puzzles

29 Apr 2010 x ?

An integer x is such that the following 4 integers x+1, 2x, 4x and 10x associated with x are of importance. x is ?

OPtion

1) 8
2) 7
3) 6
4) 9
5) 1
6) 2
7) 3
8) 4
9) 5
10) 10

Solution

6+1 = 7 (days in a week)
6*2 = 12 (months in a year)
6*4 = 24 (hours in a day)
6*10 = 60 (minutes in an hour and seconds in a minute)

Correct Option: 3 Best Solution (1)

28 Apr 2010 Age?

Date of birth of a man is 10th January 1983. His age at the present date is

OPtion

1) 27 years 6 months 18 days
2) 27 years 5 months 25 days
3) 27 years 6 months 28 days
4) 27 years 3 months 29 days
5) 27 years 4 months 25 days
6) 27 years 5 months 27 days
7) 27 years 3 months 18 days
8) 27 years 4 months 20 days
9) 27 years 4 months 10 days
10) 27 years 3 months 10 days

Solution

You can obtain the age by the following procedure

28 - 04 - 2010

- 10 - 01 - 1983

= 18 - 03 - 0027

Correct Option: 7 Best Solution (5)

27 Apr 2010 Drunk Man

A drunkard man moves 3 steps forward and than 1 step backward. In how many steps, he will fall in a
ditch which is 30 feet apart. Given that each step is 2 feet.

OPtion

1) 26
2) 27
3) 25
4) 24
5) 23
6) 28
7) 29
8) 30
9) 22
10) 31

Solution

Total displacement required is 15 steps. Since the man moves 3 steps forward and than 1 step backward,
therefore effective displacement of the man is 2 steps forward. After 24 steps effective displacement is 12 steps.
After that he will move only 3 steps and will fall in ditch.

Correct Option: 2 Best Solution (5)

26 Apr 2010 Population After 3 year?

Total population of a city is 10 lacs. If it increases by 10 % every year than after 3 year it will be

OPtion

1) 15 lacs 41 thousand
2) 13 lacs
3) 13 lacs 21 thousand
4) 12 lacs 31 thousand
5) 16 lacs 21 thousand
6) 16 lacs 31 thousand
7) 12 lacs 21 thousand
8) 13 lacs 31 thousand
9) 12 lacs 41 thousand
10) 14 lacs 41 thousand

Solution

Population after 3 years = 10 lacs * 1.1 * 1.1 * 1.1 = 13.31 lacs

Correct Option: 8 Best Solution (9)

23 Apr 2010 Possible set of x,y,z

x + y + z = 6, where x, y, z are integers from 0 to 6,
Total no. of possible set of values of x, y and z are ?

OPtion

1) 28
2) 27
3) 24
4) 21
5) 20
6) 18
7) 16
8) 30
9) 36
10) 35

Solution

Formula for solving problem = (n+r-1) (n+r-2)/(r-1) (r-2)
Here n = 6 & r = 3
On applying values we get (6+3-1) (6+3-2) / (3-1) (3-2) = 8*7/2*1 = 28

Correct Option: 1 Best Solution (11)

22 Apr 2010 Find the Number

A number x is equal to 6 less than twice of a number y formed by taking the digits of the number x in reverse order.
The number x is

OPtion

1) 65
2) 24
3) 26
4) 68
5) 84
6) 48
7) 86
8) 62
9) 56
10) 42

Solution

Let the number x is 10a + b then y = 10b + a,
Given that 10a + b = 2 (10b + a) – 6
Or 10a + b = 20b + 2a – 6
Or 8a = 19b -6
Only option is 42, which satisfies the equation

Correct Option: 10 Best Solution (11)

21 Apr 2010 Possible combination?

Number of methods of distributing 5 oranges among 3 children is

OPtion

1) 15
2) 21
3) 12
4) 24
5) 30
6) 36
7) 56
8) 42
9) 27
10) 20

Solution

Formula for solving problem = (n+r-1) (n+r-2)/(r-1) (r-2)
Here n= 5 & r =3
On applying values we get (5+3-1) (5+3-2) / (3-1) (3-2) = 7*6/2*1 = 21

Correct Option: 2 Best Solution (4)

20 Apr 2010 Board examination

A student got 68 % in the board examination. What would be his percentage, if he got 10 %
(of the total marks of the subject) more marks in physics, chemistry and mathematics? Total marks are 500
and every paper is of 100 marks.

OPtion

1) 82
2) 76
3) 78
4) 70
5) 72
6) 80
7) 74
8) 84
9) 71
10) 98

Solution

68 % = 340 marks out of 500
According to the given condition, 10 % in 3 subjects = 30 marks
Hence total marks = 340 + 30 = 370 = 74 % of 500 marks

Correct Option: 7 Best Solution (10)

19 Apr 2010 % Profit?

What will be the percentage of profit, if a shopkeeper provides a discount of 25 %
after increasing the price of an object by 50 %?

OPtion

1) 25
2) 15
3) 22.5
4) 12.5
5) 32.5
6) 40
7) 50
8) 45
9) 42.5
10) 10

Solution

Let the original price of the object is 100
After increasing the price of object by 50 %, selling price is 150
After taking a discount of 25 % on the selling price,
Price of the object for the customer is 150 * 0.75 = 112.5
Profit percentage = 112.5 – 100 = 12.5

Correct Option: 4 Best Solution (18)

16 Apr 2010 Red and Black Ball

Probability of getting 2 balls of black colour from a box containing 3 red and 4 black balls is ?

OPtion

1) 5/9
2) 3/7
3) 1/4
4) 1/3
5) 5/7
6) 3/4
7) 2/7
8) 1/7
9) 3/5
10) 4/9

Solution

No. of methods of selecting 2 black balls out of 4 black balls is 4*3/2*1 = 12/2 = 6

No. of methods of selecting 2 balls out of total 7 balls is 7*6/2*1 = 21

Hence probability = 6/21 = 2/7

Correct Option: 7 Best Solution (11)