Challenge your Brain With Math, Science & Puzzles (Entries Always Open)

This is a challenge from today.

Try to provide uniq answer

Perks

Participants

@anon30406793
:point_right:Challenge Points :

@Eren_Yeager
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@RedStorm47
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@BlackMagic123
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@User1132Kazuma
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@rajameghanan
:point_right: New Participant
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Notice !

Now you can assign points to youself in this challenge.

Each correct answer : 1 points
Each Correct or Valid Explanation : 5 points
Assigning Points Points w.e.f 15/10/22

@RedStorm47
@rajameghanan

And other participants

12 Likes

Date and Month

J, K, L, M, S, T, U, V go attend a meeting in the four months ( March, June , October & November ). The meeting held in each month on 13th and 22nd.

i ) Only two meetings held in a month
ii ) No person can attend the meeting after L
iii ) M attends the meeting in the month which has less than 31 days.
iv ) S and U attends meeting after M on date 22nd of different months, while J and K attends before M.
v ) K attends after J in the same month
vi ) V doesn’t attend the meeting in the month in which either S or L attends.

Notations :
March - M
June - J
October - O
November - N

  1. L { 22nd , nov }
  2. M { Jun/Nov }

M can not be on November because there are two persons after M. So M = Jun

  1. (S{22nd} , U { 22nd }) > M

M = 13th june . So that S and U can go on 22nd of different months

  1. M > J & K …( 1 )
  2. K > J… (2)

From (1) & (2)

U/S > S/U > M > K > J

  1. VS, VL ≠ same month

Sol
March 13 - J
March 22 - K

June 13 - M
June 22 - S

Octo 13 - V
Octo 22 - U

Nov 13 - T
Nov 22 - L

1 Like

Casting out 9 ( Digital Sum ) , Casting out 11 ( Alternating digit sum then difference ) & Casting out 3 ( Junior Digital Sum )

Digital Sum

Remainder when we divide a number by 9

Digital Sum of 8177 = 8 + 1 + 7 + 7 = 23 = 2 + 3 = 5

Digital Sum of LHS = Digital Sum of RHS:

67 × 65 = 4355
( 6 + 7 ) × ( 6 + 5 ) = ( 4 + 3 + 5 + 5 )
( 1 + 3 ) × ( 1 + 1 ) = ( 1 + 7 )
4 × 2 = 8

Junior Digital Sum
Remainder when we divide a number by 3

443 = 0443 = ( 04 - 03 ) + ( 43 - 42 ) = 1 + 1 = 2

Junior Digital Sum of LHS = Junior Digital Sum of RHS:

67 × 65 = 4355
( 67 - 66 ) × ( 65 - 63 ) = ( 43 - 42 ) + ( 55 - 54 )
1 × 2 = 1 × 2
2 = 2

Alternating Digital Sum
Alternating Digital Sum of LHS = Alternating Digital Sum of RHS:

Remainder when we divide a number by 11

67 × 65 = 4355
( 67 - 66 ) × ( 65 - 66 ) = ( 4 + 5 ) - ( 5 + 3 )
1 × 1 = 9 - 8
1 × 1 = 1
1 = 1

My favourite math trick is about calculating percentages.

For example:
How to solve 6% from 50?
We can switch the numbers and calculate: 50% from 6 = 3 (this one is easy)

And therefore 6% from 50 is also 3.

It always works :sunglasses:

4 Likes

Plz share your other tricks :slightly_smiling_face:

1 Like

Equivalent Fractions

  1. 1/2 + 1/8 = ?

= 1/2 + 1/8

= 4/8 + 1/8

= 5/8

  1. 1/2 + 1/8 + 1/16 = ?

= 1/2 + 1/8 + 1/16

= 8/16 + 2/16 + 1/16

= 11/16

  1. 1/9 + 2/3 = ?

= 1/9 + 6/9

= 7/9

  1. 1½ + 2¼ = ?

= 1½ + 2¼
= 1 + 2 + ½ + ¼
= 1 + 2 + 2/4 + ¼
= 3¾

Dont change mixed fractions into improper fractions :slightly_smiling_face::upside_down_face:

Six boxes- L, M, N, O, P, and Q are kept one above another in the stack. The lowermost box is numbered as one and the topmost box is numbered as six. The boxes are of different colors – Red, Blue, Yellow, White, Green, and Pink. All the information is not necessarily in the same order.

L is kept two boxes below the green box. L is not kept in the lowermost position. The number of boxes kept above the green box is the same as the number of boxes kept below the white box. M is kept immediately below the box which is kept three boxes above the white box. The red box is kept immediately above the Pink box. L is neither Red nor Pink. P is kept two boxes above the yellow box. P is not Green. O is neither Green nor yellow. Q is kept above box N.

Note : Left is above, right is below

Boxes are

L, M, N, O, P, and Q

Colors are
Red, Blue, Yellow, White, Green, and Pink.

Red = r
Blue = b
Yellow = y
White = w
Green = g
Pink = π

L is kept two boxes below the green box

g • L

L is not kept in the lowermost position.

L ≠ 1

The number of boxes kept above the green box is the same as the number of boxes kept below the white box.

…g = w…

The red box is kept immediately above the Pink box.

L is neither Red nor Pink

L ≠ { r, π }

P is kept two boxes above the yellow box.

P•y

P is not Green

P ≠ g

O is neither Green nor yellow.

O ≠ g, y

Q is kept above box N.

Q > N

M is kept immediately below the box which is kept three boxes above the white box

_M_w

Puzzle for All

Nine boxes P, Q, R, S, T, U, V, W, and X are placed in a stack. Three boxes are between Box P and Box W. As many boxes kept above Box P is the same as the boxes kept below Box P. Box Q is placed adjacent to Box P. Box V is placed two places below Box Q, and is not immediately above Box W. Box U is placed immediately below Box V but not at the bottom of the stack. Only one box is placed above Box X. Box S is placed above Box T and placed below Box R. R is not placed adjacent to Q.

Task : Write the sequence from top to bottom

Answer:
R
X
S
Q
P
V
U
T
W

1 Like

Some percentage tricks

11.11% = 1/9
22.22% = 2/9
aa.aa% = a/9

88.88% = ?

A. 7/9

B. 4/9

C. 8/9 :white_check_mark:

D. 6/9

1/7 = 14.28% ( 142857 )
2/7 = 28.57%
3/7 = 42.85%

88.89% of 9 + 14.28% of 7 = ?

A. 8

B. 9

C. 10

D. 11

6% of 50 + 4% of 25 = ?

A. 3

B. 4

C. 5

D. 8

1 Like

Well I need a calculator I guess :joy: for the remaining 2 problems

1 Like

Funny English Questions

Word Swap

A democracy(1) opposition(2) political(3) is the heart and soul of any functional vibrant(4).

A. 1-2 & 3-4

B. 1-4 & 2-3

C. 1-3

D. 4-1

English Sentence Puzzle

Write the words in bold letters in correct sequence to get a grammatically correct sentence :-

While one cannot political(1) the oppose(2) aspirations of people, the fact remains that acts of commission(3) and omission(4) cannot be because(5) over just glossed(6) you happen to be a political leader.

1 Like

No we dont need calculators for these simple problems.

1 Like

Less than 20 persons sit in a linear row. All persons face towards north direction. Prime number of persons sits in the row. L sits 2nd to the right of K. E sits at one of the extreme ends of the row. Five persons sit between E and J. O sits immediate left of J, who sits 3rd to the left of M. N sits 4th to the right of L. As many persons sit to the left of N as to the right of O. More than five but less than eight persons sit between M and F. F sits exactly between L and N.

Q6. How many persons sit in the row?
(a) 19
(b) 11
(c) 17
(d) 13
(e) None of these

Answer :

__ K __ L __ F __ N __ OJ __ __ M __ __ E

1 Like

Nine people are born in nine different years i.e. 1951, 1957, 1966, 1976, 1986, 1995, 1999, 2001, and 2006 but not necessarily in the same order. The age is calculated according to the year 2020.
The sum of the digits of M’s age is more than 9. Three people are born between W and M. B is born immediately after W. Two people are born between Q and B. P is born after Q and before N. Three people are born between O and Q. The age of O is not a multiple of 7. The difference between the ages of O and K is a multiple of 11. The age of D is a multiple of 9 and is born after K.

Clues:

  1. age(M) = xy ; x + y > 9
  2. W _ _ _ M / M _ _ _ W
  3. WB ( Fixed )
  4. Q _ _ B / B _ _ Q
  5. Q < P < N
  6. O _ _ _ Q or Q _ _ _ O
  7. age(O) ≠ 7n
  8. age |O - K | = 11n
  9. age D = 9n
  10. K… …D

Cancelled
1951 - 69 M
1957 - 63
1966 - 54 Q
1976 - 44
1986 - 34 W
1995 - 25 B
1999 - 21 O ( O ≠ 7n )
2001 - 19
2006 - 14 / Q’

M = xy , x + y > 9 ( 19, 69 )

69 K
63 Q
54 D ( D = 9n )
44 W
34 B
25 O ( O ≠ 7x )
21 P
19 M
14 N K’ ( D is born after K )

1951 K
1957 Q
1966 D
1976 W
1986 B
1995 O
1999 P
2001 M
2006 N

1 Like

Why you can’t divide a number by zero ?

18 ÷ 9 = ? = 2
Divisions are repeated subtraction until we get zero.
Then counts the number of steps

18 - 9 = 9 ( 1 )
9 - 9 = 0 ( 2 )

18 ÷ 0 = ?

18 - 0 = 18
18 - 0 = 18
18 - 0 = 18
18 - 0 = 18
18 - 0 = 18…






unknown number of steps
So we can’t divide by zero

Further
18 ÷ 0 ≠ infinity

18 ÷ 0 = infinity …(1)
19 ÷ 0 = infinity …(2)

18 ÷ 0 = 19 ÷ 0

18 × 0 = 19 × 0

18 = ? = 19

So , something ÷ 0 ≠ infinity

1 Like

Nine people viz. P1, P2, P3, P4, P5, P6, P7, P8 and P9 live in a building on nine different floors. The ground floor is numbered 1, the floor just above it is numbered 2 and so on till top floor which is numbered as 9 (but not necessarily in the same order). More than four persons are living above P4. Three persons are living between P6 and P1 who is living belowP8. P2 lives immediately above P9 and immediately below P8. P3 lives below P4 and above P5. Only one person is living between P5 and P7.

Solution:
P6
P8
P2
P9
P1
P4
P7
P3
P5

1 Like

Six persons P, Q, R, S, T, and U are born in same month and date of six different year viz. 1978, 1982, 1990, 1995, 2000, and 2006 but not necessarily in the same order. (All the ages will be calculated on base year 2021). All persons are related to each other.
T is the father of the one whose age is 15 years. The difference between T’s age and P’s age is the lowest. P is the mother of U, who is a male. Q is married to the sister of P, whose age is 39 years. S is the sister-in-law of R. S is older than R but younger than Q. There are only two females in the family. U is the youngest family member.

Q1. How is S related to the one whose age is 15 years?
(a) Paternal Uncle
(b) Maternal Uncle
(C) Maternal Aunt
(d) Paternal Aunt
(e) None of these

Solution :

1978 43 - T
1982 39 - P
1990 31 - Q
1995 26 - S
2000 21 - R
2006 15 - U

T is the husband of P who is the sister of S who is the wife of Q who is the brother of R who is a male.

U whose age is 15 is the son of T & P

1 Like

Waiting for new puzzles to come :wink:

1 Like

I will give new puzzles that appeared in today’s exam. I will give only question , not solution. You have to try

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Thank you

20 grateful characters

1 Like