M4maths Previous Puzzles

27 Sep 2017 Stocks

Snehal invests a part of Rs. 54,000 in 8% stock at Rs. 104 and the remainder in 12% stock at Rs. 108. If her total dividend per annum is Rs. 5600, how much does she invest in 8% stock at Rs. 104?

OPtion

1) Rs. 42300
2) Rs. 40200
3) Rs. 11070
4) Rs. 10700
5) Rs. 11700
6) Rs. 41200
7) Rs. 43200
8) Rs. 17100
9) Rs. 11770
10)Rs. None of these

Solution

Let investment in 8% stock be Rs. x.
Then, investment in 12% stock = Rs. (54000 - x).
Therefore (8/104)*x + (12/108)(54000 - x) = 5600
=> x/13 + 1/9(54000-x) = 5600
=> -4x/117 + 6000 = 5600
solving
=> x = 11700

Option 5)

Correct Option: 5 Best Solution (7)

26 Sep 2017 Rank of the word

Find Rank of the word DUSSEHRA in the dictionary of words formed by the letters of the word DUSSEHRA

OPtion

1) 5025
2) 5024
3) 5023
4) 5020
5) 5021
6) 5022
7) 5027
8) 5026
9) 5019
10) None of these

Solution

DUSSEHRA
Lets arrange the letters alphabetically = ADEHRSSU

Answer: 449221

DUSSEHRA
Lets arrange the letters alphabetically = ADEHRSSU

Words starting with A = 7!/2 = 2520
Words starting with DA = 6!/2 = 360
Words starting with DE = 6!/2 = 360
Words starting with DH = 6!/2 = 360
Words starting with DR = 6!/2 = 360
Words starting with DS = 6! = 720
Words starting with DUA = 5!/2 = 60
Words starting with DUE = 5!/2 = 60
Words starting with DUH = 5!/2 = 60
Words starting with DUR = 5!/2 = 60
Words starting with DUSA = 4! = 24
Words starting with DUSE = 4! = 24
Words starting with DUSH = 4! = 24
Words starting with DUSR = 4! = 24
Words starting with DUSSA = 3! = 6
Words starting with DUSSEA = 2! = 2
Words starting with DUSSEHA = 1! =1
and the next word is DUSSEHRA, so +1


Sum of all = 5026

Option 8)

Correct Option: 8 Best Solution (4)

25 Sep 2017 Age

A is 9 years older than B who is seven times as old as C. The total of the ages of A, B and C is 69 years. What is the product of their ages?

OPtion

1) 4244
2) 4044
3) 4944
4) 4144
5) 4544
6) 4644
7) 4744
8) 4844
9) 4344
10)None of these

Solution

Let’s assume Age of B be B years
Age of A = B+9
Age of C = B/7

Total age = B + 9 + B + B/7 = 69
Solving 15B/7 = 60
B = 28
C = B/7 = 28/7 = 4 years
A = 28+9 = 37 years
Product = 28*4*37 = 4144

Option 4)

Correct Option: 4 Best Solution (28)

22 Sep 2017 Simple Interest

A sum fetched a total simple interest of Rs. 584.1 at the rate of 6% p.a. in 5 years. What is the sum?

OPtion

1) Rs 1840
2) Rs 1850
3) Rs 1856
4) Rs 1900
5) Rs 1960
6) Rs 1950
7) Rs 1908
8) Rs 1919
9) Rs 1947
10) None of these

Solution

SI = PRT/100
P= SI*100/RT = 584.1*100/5*6 = 1947
Option 9)

Correct Option: 9 Best Solution (0)

21 Sep 2017 Root and Power

Find value of:
(7)^1.35 * (13)^0.35 * (91)^0.65 = ?

OPtion

1) 631.73
2) 636.37
3) 633.89
4) 632.10
5) 635.93
6) 637.00
7) 634.39
8) 637.53
9) 630.00
10) None of these

Solution

(7)^1.35 * (13)^0.35 * (7*13)^0.65
= (7)^1.35 (7)^0.65 * (13)^0.35 * (13)^0.65
= [(7)^(1.35+0.65)]* [(13)^(0.35+0.65)]
= (7^2) * 13^1
= 637

Correct Option: 6 Best Solution (8)

20 Sep 2017 Perfect Squares

How many factors of 82044596000 are perfect squares?

OPtion

1) 12
2) 8
3) 16
4) 18
5) 25
6) 15
7) 30
8) 40
9) 24
10) None of these

Solution

82044596000 = 2^5 * 5^3 * 29^5

Any factor of this number should be of the form 2^a * 5^b * 129^c.

For the factor to be a perfect square a,b,c have to be even.

a can take values 0, 2, 4
b can take values 0, 2
and c can take values 0, 2, 4

Total number of perfect squares = 3 * 2 * 3 = 18

Correct Option: 4 Best Solution (0)

19 Sep 2017 Distance

Two ships are sailing in the sea on the two sides of a lighthouse. The angle of elevation of the top of the lighthouse is observed from the ships are 30° and 60° respectively. If the lighthouse is 189 m high, the distance between the two ships is:

OPtion

1) 416.47 m
2) 436.47 m
3) 426.47 m
4) 446.47 m
5) 466.47 m
6) 456.47 m
7) 476.47 m
8) 486.47 m
9) 496.47 m
10)None of these

Solution

Let AB be the lighthouse where A is the bottom point of light house and C and D be the positions of the ships.
Then, AB = 189 m, Angle ACB = 30° and angle ADB = 60°.
AB/AC = tan 30° = 1/sq root(3)
=> AC = AB * sq root(3) = 189*3^(1/2)

AB/AD = tan 60° = 1/sq root(3)
=> AD = AB*1/sq root(3) = 189/*3^(1/2) = 63*3^(1/2)

CD = (AC + AD) = 3^(1/2) (189+63)
= 252*3^(1/2)
= 436.47

Correct Option: 2 Best Solution (0)

18 Sep 2017 Profit and Loss

324 bananas are bought for Rs. 900 and sold at the rate of Rs. 42 per dozen. The percentage of profit or loss is:

OPtion

1) 23 % Profit
2) 24 % Profit
3) 25 % Profit
4) 26 % Loss
5) 27 % Profit
6) 28 % Profit
7) 29 % Profit
8) 24.5 % Profit
9) 26.5 % Loss
10) None of these

Solution

Cost of 1 banana= 900/324 = 2.777778
Selling price of 1 banana = 42/12 = Rs. 3.5

As SP > CP so its profit
So Profit % = (3.5 - 2.777778 )*100/2.777778 = 26 %
Option 10)

Correct Option: 10 Best Solution (0)

15 Sep 2017 Simple Interest

A sum fetched a total simple interest of Rs. 256 at the rate of 5% p.a. in 5 years. What is the sum?

OPtion

1) Rs 1000
2) Rs 1024
3) Rs 1020
4) Rs 1010
5) Rs 1016
6) Rs 1100
7) Rs 1030
8) Rs 1050
9) Rs 1036
10) None of these

Solution

SI = PRT/100
P= SI*100/RT = 256*100/5*5 = 256*4 = 1024
Option 2)

Correct Option: 2 Best Solution (0)

14 Sep 2017 Profit and Loss

Abdul buys an old bicycle for Rs. 1875 and spends Rs. 350 on its repairs. If he sells the bicycle for Rs. 2775, his gain percent is:

OPtion

1) 27.02 %
2) 23.82 %
3) 24.09 %
4) 27.05 %
5) 25.92 %
6) 24.72 %
7) 25.08 %
8) 24.42 %
9) 23.62 %
10) None of these

Solution

Cost Price (C.P.) = Rs. ( 1875 + 350) = Rs. 2225

Selling Price (S.P.) = Rs. 2775

Gain = (S.P.) - (C.P.) = Rs.(2775 - 2225) = Rs. 550

Gain % = (550/2225)*100 = 24.7191 = ~24.72 %

Option 6)

Correct Option: 6 Best Solution (9)