M4maths Previous Puzzles

13 Sep 2019 LCM

Two numbers are in the ratio 7 : 11. If their L.C.M. is 308. what is sum of the numbers?

OPtion

1) 110
2) 78
3) 66
4) 64
5) 63
6) 68
7) 72
8) 60
9) 82
10) None of these

Solution

"Let the numbers be 7x and 11x
LCM of 7x and 11x is 77x

So as per question 77x = 308
=> x= 4

7x = 7*4 = 28 and 11x = 11*4 = 44

Sum of the numbers = 28+44 = 72

Correct Option: 7 Best Solution (3)

12 Sep 2019 Mixture

A mixture contains sugar solution and colored water in the ratio 5 : 8. If 22 liters of colored water is added to the mixture, the ratio becomes 3 : 7. Find the initial quantity of sugar solution in the given mixture (in liters).

OPtion

1) 20
2) 24
3) 15
4) 16
5) 30
6) 45
7) 32
8) 25
9) 36
10) None of these

Solution

The initial ratio is 5 : 8.
Let ‘k’ be the common ratio.
=> Initial quantity of sugar solution = 5 k
=> Initial quantity of colored water = 8 k
=> Final quantity of sugar solution = 5 k
=> Final quantity of colored water = 8 k + 22
Final ratio = 5 k : 8 k + 22 = 3 : 7
=> k = 6
Therefore, initial quantity of sugar solution in the given mixture (in liters) = 5 k = 30 liter

Correct Option: 5 Best Solution (0)

11 Sep 2019 Age

The present ages of A,B and C are in proportions 2:4:7. Four years ago, the sum of their ages was 66. What is the product of their present ages?

OPtion

1) 7500
2) 12960
3) 3840
4) 12096
5) 30720
6) 24000
7) 43740
8) 42000
9) 19440
10) None of these

Solution

Answer: 12096 years


Four years ago sum of Ages of A, B and C = 66
Four years later i.e. sum of current ages of A, B and C = 66 + 3*4 = 78

Present Age of A = 78*2/(2+4+7) = 12 years

Present Age of B = 78*4/(2+4+7) = 24 years
Present Age of C = 78*7/(2+4+7) = 42 years

Product of their ages = 12096

Option 4)

Correct Option: 4 Best Solution (5)

10 Sep 2019 Simplification

There are two buildings P and Q. If 35 persons are sent from P to Q, then the number of persons in each building is the same. If 60 persons are sent from Q to P, then the number of persons in P is double the number of persons in Q. How many persons are there in building P?

OPtion

1) 250
2) 320
3) 325
4) 290
5) 335
6) 315
7) 340
8) 365
9) 350
10) None of these

Solution

Let number of persons in building P be P and
number of persons in building Q be Q

P-35 = Q+35
=> P = Q + 70 ---- (i)

P+60= 2(Q-60)
=> P + 180 = 2Q ---- (ii)

Putting value of P from (i) in (ii)
Q+ 70 + 180 = 2Q
Q = 250
P = 320

Correct Option: 2 Best Solution (3)

09 Sep 2019 Simple Interest

At what simple interest rate percent per annum will a sum of money triple in 19 years.

OPtion

1) 10.50
2) 10.52
3) 9.33
4) 10.50
5) 10.53
6) 10.14
7) 10.75
8) 9.75
9) 10.66
10) None of these

Solution

SI = PRT/100

SI = 2P

So 2P = P*R*19/100
= R= 200/19 = 10.53
Option 5)

Correct Option: 5 Best Solution (0)

06 Sep 2019 Profit and Loss

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

OPtion

1) 12.98%
2) 12.16%
3) 12.061%
4) 12.89%
5) 12.49%
6) 12.08%
7) 12.61%
8) 12.53%
9) 12.77%
10) None of these

Solution

Let the CP of 1000 gm item be Rs. 1000
CP of 888 GM item = Rs 888
SP of 888 gm item = Rs 1000

Profit %= (1000 - 888)*100/880 = 112*100/888 = 12.61 %

Correct Option: 7 Best Solution (0)

05 Sep 2019 Stocks

The market value of a 7.5% stock, in which an income of Rs. 1500 is derived by investing Rs. 5000, brokerage being 3/4 %, is:

OPtion

1) 25.00
2) 25.75
3) 25.50
4) 24.15
5) 24.25
6) 24.96
7) 24.75
8) 24.46
9) 24.60
10) None of these

Solution

For an income of Rs. 1500, investment = Rs. 5000

For an income of Rs. 7.5, investment = Rs. (5000/1500) * 7.5 = 25
For a Rs. 100 stock, investment = Rs. 25

Market value of Rs. 100 stock = Rs. 25 - 0.75 = Rs. 24.25

Option 5)

Correct Option: 5 Best Solution (1)

04 Sep 2019 Factors

How many factors of 105488578125 are odd number?

OPtion

1) 200
2) 48
3) 180
4) 300
5) 280
6) 160
7) 360
8) 320
9) 40
10) None of these

Solution

105488578125 = 3^9 * 5^6 * 7^3

Any factor of this number should be of the form 3^a * 5^b * 7^c.

For the factor to be a odd number a,b,c can take any value as product of 3 odd numbers would always be odd
a can take values 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
b can take values 0, 1, 2, 3, 4, 5, 6
and c can take values 0, 1, 2, 3

Total number of odd factor = 10 * 7 * 4 = 280

Correct Option: 5 Best Solution (0)

02 Sep 2019 Series

What is the next term of following series:
113, 127, 131, 137, 139

OPtion

1) 141
2) 144
3) 143
4) 145
5) 149
6) 146
7) 147
8) 148
9) 140
10) None of these

Solution

Series is formed by prime number starting at 113 so next prime number is 149
Option 5)

Correct Option: 5 Best Solution (0)

30 Aug 2019 Handshakes

In a party attended by 27 persons, each clinch their glass with every other. How many glass clinches?

OPtion

1) 289
2) 378
3) 325
4) 351
5) 320
6) 301
7) 310
8) 305
9) 316
10) None of these

Solution

Total no. of person = 27
Total no. of glass clinches = n(n-1)/2
=27*26/2
= 351

Correct Option: 4 Best Solution (0)