M4maths Previous Puzzles

08 Nov 2019 Profit and Loss

A shopkeeper sells his goods at cost price but uses a weight of
860 gm instead of kilogram weight. What is his profit percentage?

OPtion

1) 16.28%
2) 16.16%
3) 16.061%
4) 16.89%
5) 16.49%
6) 16.08%
7) 16.61%
8) 16.53%
9) 16.77%
10) None of these

Solution

Let the CP of 1000 gm item be Rs. 1000
CP of 860 GM item = Rs 860
SP of 860 gm item = Rs 1000

Profit %= (1000 - 860)*100/880 = 120*100/860 = 16.28 %

Correct Option: 1 Best Solution (4)

07 Nov 2019 Ratio

If 4 kg of kiwi cost as much as 16 kg of banana, and the cost of 5 kg of kiwi and 16 kg of banana is Rs 1080, what is the cost of kiwi per kg?

OPtion

1) 100
2) 105
3) 110
4) 115
5) 120
6) 125
7) 130
8) 135
9) 140
10) None of these

Solution

Let the cost of kiwi per kg be Rs x, and the cost of banana per kg be Rs y.
=> 4x = 16y or x = 4y
Also, 5x+ 16y = 1080
Or, 5x+4x = 1080
Or, x = 120
Therefore, the cost price of kiwi per kg = Rs. 120

Correct Option: 5 Best Solution (0)

06 Nov 2019 Permutation

How many five digit numbers can be formed by using 3, 4, 5, 6, 7 if 6 is necessarily taken at hundred's
place and 4 is not allowed at unit's place.
Note: Repetition of numbers is not allowed.

OPtion

1) 18
2) 22
3) 27
4) 20
5) 16
6) 24
7) 23
8) 21
9) 28
10) None of these

Solution

6 is necessarily taken at hundred's place and 4 is not allowed at unit's place,
hence number of methods = 1*3*3*2*1 = 18

Correct Option: 1 Best Solution (3)

05 Nov 2019 Arithmetic

A number decreased by 13 is equal to the difference between 18 and 7. What is the number

OPtion

1) 11
2) 21
3) 19
4) 18
5) 22
6) 24
7) 26
8) 27
9) 29
10) None of these

Solution

18-7 = 11
=> 11 13 = 24

Correct Option: 6 Best Solution (3)

04 Nov 2019 Decimal Representation

The age of a man is thirty nine years and eight and half a month. What is its age in decimal representation?

OPtion

1) 39.61
2) 39.62
3) 39.85
4) 39.81
5) 39.67
6) 39.68
7) 39.89
8) 39.71
9) 39.91
10) None of these

Solution

8.5/12 = 0.71

Correct Option: 8 Best Solution (0)

01 Nov 2019 Simple Interest

A sum of money at simple interest amounts to Rs. 690 in 3 years and to Rs. 720 in 4 years. The sum is:

OPtion

1) 750
2) 650
3) 640
4) 550
5) 500
6) 700
7) 600
8) 625
9) 450
10) None of these

Solution

S.I. for 1 year = Rs. (720 - 690) = Rs. 30.

S.I. for 3 years = Rs.(30 x 3) = Rs. 90.

Principal = Rs. (690 - 90) = Rs. 600.

Correct Option: 7 Best Solution (5)

31 Oct 2019 Age

Mr. Tanpura says to his son Guitar: " My age was two years more than 7 times of yours age before
25 & 1/2 years and after 7 & 1/2 a year, my age will be twice of yours age of 1/2 a year before".
What will be the age of Guitar after 10 and 1/2 a year.

OPtion

1) 43
2) 42
3) 41
4) 40
5) 48
6) 39
7) 50
8) 38
9) 28.5
10) None of these

Solution

Let the age of tanpura be x and guitar be y.
We get following equations from given conditions:
x - 25.5 = 7 (y - 25.5) + 2
x + 7.5 = 2(y - 0.5)

Solving we get y = 28.5
After 10.5 years, age of y = 39

Correct Option: 6 Best Solution (0)

30 Oct 2019 Area

If the diagonal of a rectangle is 47cm long and its perimeter is 96 cm. Find the area of the rectangle in sq. cm.

OPtion

1) 95
2) 48.5
3) 47.5
4) 94
5) 49.5
6) 93
7) 46.5
8) 92
9) 45.5
10) None of these

Solution

Let length = x and breadth = y then

2(x+y) = 96 => x+y = 48
x²+y² = 47² = 2209
now (x+y)² = 39² = 2304
=> x²+y²+2xy= 2304
=> 2209 + 2xy = 2304
=> xy = 47.5
area = xy = 47.5 sq.cm

Option 3)

Correct Option: 3 Best Solution (0)

29 Oct 2019 Even Number

How many factors of 42996970800 are even numbers?

OPtion

1) 750
2) 800
3) 640
4) 960
5) 580
6) 150
7) 125
8) 648
9) 240
10) None of these

Solution

42996970800 = 53^1 * 73^1 * 7^3 * 5^2 * 2^4 * 3^4

Any factor of this number should be of the form 53^a * 73^b * 7^c * 5^d * 2^e * 3^f.

For the factor to be an even number e should be non zero.

a can take values 0, 1
b can take values 0, 1
c can take values 0, 1, 2, 3
d can take values 0, 1, 2
e can take values 1, 2, 3, 4
and f can take values 0, 1, 2, 3, 4

Total number of odd factors = 2*2*4*3*4*5 = 960

Option 4)

Correct Option: 4 Best Solution (2)

28 Oct 2019 Calendar

Today is Monday. After 160 days, it will be :

OPtion

1) Monday
2) Tuesday
3) Wednesday
4) Thursday
5) Friday
6) Saturday or Sunday
7) Sunday or Monday
8) Saturday
9) Sunday
10) None of these

Solution

160 days = 22 weeks 6 days
Hence if today is Monday, After 160 days, it will be = (Monday + 6 days)
= Sunday

Correct Option: 9 Best Solution (5)