M4maths Previous Puzzles

16 Dec 2015 Price

A boy purchases three itoms of consecutive prices. The number of purchased itoms are 1, 2 & 3. He pays Rs 115 to shopkeeper. If all prices are taken in integers, then out of 10 choices, the price of that itom, whose 3 pieces are purchased, is

OPtion

1. 18
2. 20
3. 21
4. 22
5. 24
6. 17
7. 16
8. 26
9. 12
10.28

Solution

6 cases arise
1x + 2(x + 1) + 3(x + 2) = 115 => x ≠ integers
1x + 3(x + 1) + 2(x + 2) = 115 => x = 18
2x + 1(x + 1) + 3(x + 2) = 115 => x = 18
2x + 3(x + 1) + 1(x + 2) = 115 => x ≠integer
3x + 1(x + 1) + 2(x + 2) = 115 => x ≠ integer
3x + 2(x + 1) + 1(x + 2) = 115 => x ≠ integer
Since x = 18, hence solutions are 19 & 20 according to 2nd and 3rd conditions given above,
Out of 10 choices, 20 is correct
Option 2)

Correct Option: 2 Best Solution (16)

15 Dec 2015 Age Problem

The age of a mother is 4 times that of his son. Five year ago, the mother was nine times as old as his son was at that time. The present age of the mother is

OPtion

1) 44 years
2) 40 years
3) 46 years
4) 32 years
5) 36 years
6) 31 years
7) 32 years
8) 28 years
9) 42 years
10)27 years

Solution

Let the son's age be x then, mother's age = 4x
Therefore
4x-5 = 9(x-5)
5x = 40
x = 8
x = 32 years
Option 4)

Correct Option: 4 Best Solution (13)

14 Dec 2015 Sequence

What is the next number of the following sequence
67, 137, 837, 1537, 8537, 15537, .......

OPtion

1) 155537
2) 15337
3) 15377
4) 11537
5) 85537
6) 55377
7) 85553
8) 85337
9) 855337
10)153337

Solution

67
6+7 = 13(7) = 137 (Sum of first and last digit and keep remaining digits as it is)
1+7 = 8(37) = 837 ( ---------- )
8+7 = 15(37) = 1537 ( --------- )
1+7 = 8(537) = 8537 ( ---------- )
8+7 = 15(537) = 15537 ( ---------- )
Similarly
1+7 = 8(5537) = 85537
.....

Correct Option: 5 Best Solution (43)

11 Dec 2015 Age Problem

Mohan's ages is 1/6 th of his father's age. The father's age will be twice of Suresh's ages, after 10 years. If Suresh's eight birhtday was celebrated 2 years before, what is Mohan's present age?

OPtion

1) 3 years
2) 22 years
3) 18 years
4) 6 years
5) 17 years
6) 16 years
7) 8 years
8) 28 years
9) 25 years
10)None of these

Solution

Suresh's present age = 10 yr
Suresh's age after 10 yr = 20 yr
Father's age after 10 yr = 40 yr
Father'a age now 30 yr
Mohan's age now 1/6 * 30 = 5

Option 10) None of these

Correct Option: 10 Best Solution (32)

10 Dec 2015 Time and distance

If a man takes as much time in running 10 m as a car takes in covering 25 m, the distance covered by the man during the time car covers 1 km is

OPtion

1) 340 m
2) 180 m
3) 90 m
4) 400 m
5) 450 m
6) 250 m
7) 390 m
8) 290 m
9) 300 m
10)350 m

Solution

25:10 = 1000 : x
x = 400 m
Option 4)

Correct Option: 4 Best Solution (10)

09 Dec 2015 Cube

A cube whose edge measures 8 cm is cut into cubes whose edge measures 1.0 cm. Find the ratio of the surface area of the original cube to the sum of the surface areas of the new cubes.

OPtion

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

Solution

Sum of volume of new cubes = Volume of original cube.
using this to find number of cubes, we can find ratio of surface areas.
Volume of original cube = 8^3 = 512 cm^3
Volume of new cube = 1^3 = 1 cm^3
So, number of new cubes = Volume of original cube/Volume of new cube
=512
Surface area of original cube = 6*8^2 = 384 cm^2
Surface area of new cube = 6 1^2 = 6 cm^2
total surface area of all cubes = 512*6 = 3072 cm^2
Ratio of surface area of original cube to sum of surface areas of new cube
348/3072 = 1/8
1:8
Option 5)

Correct Option: 5 Best Solution (2)

08 Dec 2015 A B C changed

If symbols of alphabets (without any change in their sense and meaning) would be as given below L M V A K B N C P I D Y O S E Q R F T H G J U W Z X then "WORLDCUP" would be written as

OPtion

1) UEFAYVGQ
2) UEFYKVGQ
3) UEFYAMQG
4) UEFYAVGR
5) UFEYAVGQ
6) UEFYAVQG
7) UEFVYAGQ
8) UEFYAVJQ
9) UEFYAVGQ
10)UEFZAVGQ

Solution

On comparing this sequence of alphabet with basic sequence we get the new word for WORLDCUP.

Correct Option: 9 Best Solution (5)

07 Dec 2015 Sequence

What is the next number of the following sequence
38, 49, 62, 70,.......

OPtion

1) 76
2) 82
3) 91
4) 83
5) 86
6) 79
7) 77
8) 92
9) 97
10)99

Solution

38
38+11 = 49
49+13 = 62
62+8 = 70
Similarly
70+7 = 77
Option 7)

Correct Option: 7 Best Solution (13)

04 Dec 2015 Stock and Shares

Find the cost of Rs.6400, 8% stock at par (brokerage 1/8%)

OPtion

1) Rs.6412
2) Rs.6416
3) Rs.6402
4) Rs.6404
5) Rs.6408
6) Rs.6418
7) Rs.6424
8) Rs.6420
9) Rs.6410
10)Rs.6450

Solution

C.P of Rs.100 stock = Rs.(100 + 1/8) = Rs. 801/8
C.P. of Rs. 6400 stock = Rs.(801*6400 / 8*100)
= Rs. 6408
Option 5)

Correct Option: 5 Best Solution (0)

03 Dec 2015 Dimensions

A office room is half as long again as it is broad. The cost of carpeting the office room at Rs.18 per m^2 is Rs.972 and the cost of white-washing the four walls at Rs.6 per m^2 is Rs.1080. Find the height of the office room.

OPtion

1) 4 m
2) 8 m
3) 6 m
4) 10 m
5) 6.5 m
6) 5.5 m
7) 11 m
8) 12 m
9) 8 m
10)9 m

Solution

Let breadth = x, length = 3/2x and height = y metres
Area of the floor = 972/18 m^2 = 54 m^2
Therefore x * 3/2 * x = 54 or x^2 = 36 x = 6
Breadth = 6 m and length = 3/2 * 6 m = 9 m
Now area of 4 walls = 1080/6 m^2 = 180 m^2
Therefore 2(9+6)*y = 180
y = 6
Height = 6 m
Option 3)

Correct Option: 3 Best Solution (0)