M4maths Previous Puzzles

12 May 2020 Arithmetic

The sum of squares of three successive integers is 41774. Sum of these integers is?

OPtion

1) 344
2) 346
3) 364
4) 346
5) 346
6) 354
7) 376
8) 326
9) 328
10) None of these

Solution

(a-1)^2 + a^2 + (a+1)^2 = 41774
=> a^2 -2a + 1 + a^2 + a^2 + 2a + 1 = 41774
=> 3a^2 + 2 = 41774
=> a^2 = (20174-2)/3 = 13924
=> a = 118
So the 3 numbers are 117, 118 and 119 and their sum is 354

Correct Option: 6 Best Solution (0)

11 May 2020 Probability

An alphabet is randomly selected from the word INDIA
What is the probability that it would be I?

OPtion

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

Solution

Total alphabets = 5
Number of Is = 2

Probability = 2/5

Correct Option: 4 Best Solution (6)

08 May 2020 Stocks

The market value of a 8.5% stock, in which an income of Rs. 2020 is derived by investing Rs. 20200, brokerage being 1/4 %, is:

OPtion

1) 84.75
2) 85.25
3) 84.25
4) 84.50
5) 85.75
6) 85.50
7) 83.75
8) 84.00
9) 83.00
10) None of these

Solution

For an income of Rs. 2020, investment = Rs. 20200

For an income of Rs. 8.5 investment = Rs. (2020/20200) * 8.5 = 85
For a Rs. 100 stock, investment = Rs. 85

Market value of Rs. 100 stock = Rs. 85 - 0.25 = Rs. 84.75

Correct Option: 1 Best Solution (2)

07 May 2020 Series

Log 10, log 10, log 100, log 1000, log 100000, log 100000000, ?

Assume all logs to the base 10

OPtion

1) log 100000000
2) log 1000000000
3) log 10000000000
4) log 100000000000
5) log 1000000000000
6) log 10000000000000
7) log 100000000000000
8) log 1000000000000000
9) log 10000000000000000
10) None of these

Solution

Its a Fibonacci represented in terms of Log
1, 1, 2, 3, 5, 8, 13...
So log 10000000000000 =13

Correct Option: 6 Best Solution (0)

06 May 2020 Age

Simran's father was 23.5 years of age when she was born while her mother was 26.5 years old when her brother eight years younger to her was born. What is the difference between the ages of her parents?

OPtion

1) 0
2) 5
3) 9
4) 3
5) 4
6) 1
7) 6
8) 7
9) 8
10) None of these

Solution

Age of Simran's father when she was born = 23.5

Age of Simran's mother when Simran was born = 26.5 −8 = 18.5

Required difference of age = 23.5 - 18.5 = 5 years

Correct Option: 2 Best Solution (4)

05 May 2020 CODE DECODE

If
FRAUD = 50,
CROOK = 62,
CHEAT = 37
then whats the code for CHINA?

OPtion

1) 420
2) 35
3) 16
4) 39
5) 36
6) 33
7) 45
8) 40
9) 43
10) None of these

Solution

A=1, B=2, C=3, ....Z=26

Code is formed by Sum of alphabet positions

So CHINA = 3+8+9+14+1 =35

Correct Option: 2 Best Solution (6)

04 May 2020 Age

Present ages of Jadeja and Pandya are in the ratio of 5 : 4 respectively. Three years hence, the ratio of their ages will become 11 : 9 respectively. What is Jadeja;s present age in years?

OPtion

1) 20
2) 12
3) 18
4) 16
5) 25
6) 24
7) 30
8) 36
9) 35
10) None of these

Solution

Let the present ages of Jadeja and Pandya be 5x years and 4x years respectively.

(5x+3)/(4x+3) = 11/9

=> 9(5x + 3) = 11(4x + 3)
=> 45x + 27 = 44x + 33
=> 45x - 44x = 33 - 27

x = 6.

Jadeja's present age = 5x = 5*6 = 30 years

Correct Option: 7 Best Solution (4)

01 May 2020 Work and Time

Sachin can do a work in 15 days and Virat in 20 days. If they work on it together for 4 days, then the fraction of the work that is left is

OPtion

1) 1/15
2) 53/60
3) 2/15
4) 3/15
5) 8/15
6) 6/15
7) 7/15
8) 11/15
9) 4
10) None of these

Solution

Sachin's 1 day's work = 1/15 Virat's 1 day's work = 1/20

(Sachin + Virat)'s 1 day's work = (1/15 + 1/20) = 7/60


(Sachin + Virat)'s 4 day's work = 4* (7/60) = 7/15

Remaining work = 1 - 7/15 = 8/15

Correct Option: 5 Best Solution (0)

30 Apr 2020 Coconuts

Muthuraman has 3 bags. He goes to a river to collect coconuts.
In each bag he can carry maximum 30 coconuts, so, in all 3 bags he can carry 90 coconuts. On his way back to home he has to cross 30 toll gates. The rules to cross the toll gates are as below:
- On each of the toll gate, as a tax the person has to give as many coconuts as the number of bags he is carrying

What is the maximum number of coconuts which Muthuraman can take home?

OPtion

1) 0
2) 5
3) 9
4) 3
5) 17
6) 23
7) 26
8) 25
9) 24
10) None of these

Solution

For first 10 toll gates he will carry all 3 bags and would give 10x3 = 30 coconuts

Coconuts left = 90-30 = 60

Beyond 10th toll gate, he will start carrying coconut only in 2 bags till he is left with 30 coconuts.

So for next 15 toll gates he will carry 2 bags and give 2 coconut at each toll gate

So Coconuts left = 60 - 15x2 = 30

Now, he will keep all coconuts in a single bag so that he has to give only one coconut at each of the remaining 5 gates gate.

Finally he would be left with 30-5 = 25 coconuts

Correct Option: 8 Best Solution (9)

29 Apr 2020 Probability

Jinping decides to randomly tweet a 3 letter word from English alphabets (without repetition of any alphabet).

What is the probability that he will tweet LIE?

OPtion

1) 1/17576
2) 1/17076
3) 1/17596
4) 1/17516
5) 1/12600
6) 1/13600
7) 1/14600
8) 1/15680
9) 1/15600
10) None of these

Solution

For the first place we have 26 alphabets, for second we have 25 alphabets and for 3rd we have 24
So total possible outcomes:
26x25x24 = 15600

Number of positive outcome of typing the word LIE = 1x1x1 = 1

Probability = 1/15600

Correct Option: 9 Best Solution (4)