M4maths Previous Puzzles

06 Oct 2021 Length of room

The cost of tiling a room 28 m long with a tile 35 cm wide at Rs.4.50 per metre is Rs.810. The breadth of the room is??

OPtion

1. 2.96
2. 7.5
3. 6.4
4. 2.50
5. 2.25
6. 3.25
7. 3.30
8. 3.50
9. 4.20
10. None of the above

Solution

Length of the tile =(Total cost of tiling /Rate per m tile)

=(8100/45)m=180m
As the tiles covers the whole room.

So, Area of the room = Area of the tiles

=(180×35/100)square m= 63 sq m

∴ Breadth of the room =(Area/Length)=(63/28)m

= 2.25 m

Correct Option: 5 Best Solution (1)

05 Oct 2021 Work

40 workers can build a house in 30 days. After ‘y’ days, 15 workers left the work and the whole work was completed in 42 days. find number of days after which 15 workers left the work?

OPtion

1. 17
2. 21
3. 30
4. 11
5. 15
6. 19
7. 13
8. 10
9. 12
10. None of the above

Solution

Total work =40 × 30=1200 units
ATQ, 40y+25×(42-y)=1200
40y + 1050 – 25y =1200
15y = 150
y=10

Correct Option: 8 Best Solution (3)

04 Oct 2021 Breadth

lawn is in the form of a rectangle having its breadth and length in the ratio 2 : 5. The area of the lawn is 1/8 hectare. The breadth of the lawn is (Approx. Value)

OPtion

1. 25
2. 24.6
3. 26.50
4. 26.36
5. 24.35
6. 22.36
7. 20.58
8. 21.56
9. 30.33
10. None of the above

Solution

1/8 hectare = 1/8 x10000 sq. Metre
= 1250 sq. metre
2x X 5x= 1250
x^2 = 1250 / 10
x^2 = 125
x = 11.18
Width = 2x = 2 x 11.18 = 22.36 metre

Correct Option: 6 Best Solution (3)

01 Oct 2021 letter

The width of all the three lines of the letter H is 3 mm. Length of two side lines are 6 mm. each and that of the middle line is 5 mm. The cost of the letter H in the birthday cake is 18 rupee/mm^2 in golden shining. Total cost for writing H in the cake will be

OPtion

1) 280 rupee
2) 320 rupee
3) 340 rupee
4) 380 rupee
5) 400 rupee
6) 420 rupee
7) 828 rupee
8) 500 rupee
9) 580 rupee
10) none of these

Solution

Total Area of the letter H is:
2(6*3) + (5*3) = 51 mm^2
As rate is 18 rupee/mm^2
51 * 18 = 918 rupee

Correct Option: 10 Best Solution (0)

30 Sep 2021 Partnership

L, M, N enter into a partnership work with L receives Rs. 54000. If out of a total profit of Rs. 4500. L gets Rs. 1500 and M gets Rs.2100. N gets Rs.900, then M capital is

OPtion

1. 70500
2. 75600
3. 72700
4. 74900
5. 72000
6. 73650
7. 74874
8. 79980
9. 78000
10. None of the above

Solution

Profit ratio is L:M:N=1500:2100:900
L:M:N=5:7:3.
Let L,M,N be 5x,7x,3x
L’s receives,5x=54000,x =10800
M’s receives,7 *10800 = Rs.75600

Correct Option: 2 Best Solution (2)

29 Sep 2021 LCM

The length of a rectangular hall is 5m more than its breadth. The area of the hall is 750m^2. The length of the hall is :

OPtion

1. 25m
2. 28m
3. 32m
4. 35m
5. 33m
6. 40m
7. 30m
8. 20m
9. 15m
10. None of the above

Solution

Let the breadth of rectangular hall = x m.
length = (x + 5) m.
Area of hall = L× B
750 = (x + 5) x
x^2 + 5x – 750 = 0
x^2 + 30x – 25x – 750 = 0
x (x + 30) – 25 (x + 30) = 0
(x – 25) (x + 30) = 0
x = 25, as x cannot be negative.
Length of hall = x + 5
= 25 + 5 = 30 m

Correct Option: 7 Best Solution (1)

28 Sep 2021 AVERAGE

The average of 5 successive integers is 12.Their product will be

OPtion

1) 134560
2) 154680
3) 165490
4) 213460
5) 234240
6) 236580
7) 240240
8) 283450
9) 324340
10) none of these

Solution

Let, consider 5 consecutive integers: x,x+1,x+2,x+3,x+4
Sum, (5x+10)= 60; then x=10;
so, 10*11*12*13*14 = 240240.

Correct Option: 7 Best Solution (5)

27 Sep 2021 percentage

x % of y is z, then z % of y is

OPtion

1) (x^2)/y
2) x/y
3) y/(z^2)
4) (z^2)/x
5) (y^2)/x
6) x/(y^2)
7) z/(x^2)
8) x/(z^2)
9) z/y
10) none of these

Solution

x % of y is z,
y*x/100 = z ; y /100 = z/x

z% of y = y*z/100 = z*y/100 = z*z/x = (z^2)/x .. option 4

Correct Option: 4 Best Solution (3)

24 Sep 2021 Number Sequence

What is the next no of following sequence
1, 4, 27, 256, 3125, ....

OPtion

1) 6,561
2) 7,776
3) 15,625
4) 32,768
5) 46,656
6) 59,049
7) 65,536
8) 1,17,649
9) 2,29,936
10) None of these

Solution

1^1=1
2^2=4
3^3=27
4^4=256
5^5=3125
6^6=46656

Correct Option: 5 Best Solution (0)

23 Sep 2021 Age

The total age of 6 persons is 114. Besides the eldest the avg. of other 5 persons is 16. If all ages are in AP, then age of youngest one will be

OPtion

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

Solution

The total age of 6 persons is 114.
Besides the eldest the avg. of other 5 persons is 16.

Sum of ages of 5 persons = 16*5=80
age of eldest = 114-80=34
if age of youngest is x and all ages are in AP
then
6*(x+34)/2 =114
3x=114-102=12
x=4

so age of youngest is 4 yrs.

Correct Option: 3 Best Solution (0)