M4maths Previous Puzzles

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)

22 Sep 2021 four-digit number

Suppose 4 digits 2, 4, 6, and 9 are given. You have to make a four-digit number. In how many ways it can be done, if repetition of the numbers does not allowed.

OPtion

1. 15
2. 22
3. 26
4. 28
5. 256
6. 24
7. 36
8. 148
9. 64
10. None of the above

Solution

Required number of 4 digit number = n! / (n – r)!
= 4! / (4 – 4)! = 24

Correct Option: 6 Best Solution (3)

21 Sep 2021 H.C.F and L.C.M

The H.C.F and L.C.M of two numbers are 12 and 336 respectively. If one of the number is 84, the other is

OPtion

1. 36
2. 108
3. 72
4. 96
5. 60
6. 84
7. 48
8. 120
9. 132
10. None of the above

Solution

First number × second number = HCF × LCM
84 × second number = 12 × 336
So, Second number = (12 x 336) / 84
=48

Correct Option: 7 Best Solution (0)

20 Sep 2021 Trigonometry

If Ɵ be acute angle and tan (4Ɵ – 50°) = cot (50° – Ɵ), then the value of Ɵ in degrees is:

OPtion

1. 20
2. 50
3. 40
4. 30
5. 45
6. 60
7. 90
8. 75
9. 35
10. None of the above

Solution

tan (4Ɵ – 50°) = cot (50° – Ɵ)
tan (4Ɵ – 50°) = tan (90° – (50° – Ɵ))
4Ɵ – 50° = 90° – (50° – Ɵ)
4Ɵ – 50° = 90° – 50° + Ɵ
4Ɵ – 50° = 40° + Ɵ
4Ɵ – Ɵ = 40° + 50°
3Ɵ = 90°
Ɵ = 90 / 3 ° = 30°

Correct Option: 4 Best Solution (3)

17 Sep 2021 Speed

The distance between 2 places R and S is 42 km. Anita starts from R with a uniform speed of 4 km/h towards S and at the same time Romita starts from S towards R also with some uniform speed.
They meet each other after 6
hours. The speed of Romita is?

OPtion

1. 18 km/hour
2. 6 km/hour
3. 20 km/hour
4. 8 km/hour
5. 16 km/hour
6. 18 km/hour
7. 3 km/hour
8. 13 km/hour
9. 15.5 km/hour
10. None of the above

Solution

Speed of Romita = x kmph
(let)
Distance = Speed × Time
According to the question,
4 × 6 + x × 6 = 42
Þ 6x = 42 – 24 = 18
Þ x = 18 ÷ 6 = 3 kmph

Correct Option: 7 Best Solution (3)