Tag: math & puzzles

Questions Related to math & puzzles

The average age of 10 members of a committee is the same as it was 4 years ago, because an old member has been replaced by a young member. Find how much younger is the new member ?
general knowledge math & puzzles

  1. 30 years

  2. 40 years

  3. 80 years

  4. 60 years

Show answer
Correct Option: B

2 hours after a freight train leaves Delhi a passenger train leaves the same station travelling in the same direction at an average speed of 16 km/hr. After travelling 4 hrs the passenger train overtakes the freight train. The average speed of the freight train was?
general knowledge math & puzzles

  1. 40

  2. 30

  3. 80

  4. 60

Show answer
Correct Option: A
Explanation:

To solve this question, the user needs to know the concept of relative speed and the formula of distance, speed and time.

Let's assume that the average speed of the freight train is x km/hr.

As the passenger train overtakes the freight train after travelling for 4 hours, this means that the passenger train has covered the same distance as the freight train in 4 hours.

The distance covered by the freight train in 4 hours can be calculated as:

Distance = Speed * Time

Distance = x * 4

Distance = 4x km

Now, let's consider the relative speed between the two trains. The passenger train is travelling at an average speed of 16 km/hr and the freight train is travelling at an average speed of x km/hr.

Relative speed = (16 - x) km/hr

As the passenger train overtakes the freight train, the distance covered by both trains is the same. Thus, we can equate the distance covered by the passenger train to the distance covered by the freight train:

Distance covered by passenger train = Distance covered by freight train

Speed of passenger train * Time taken by passenger train = Speed of freight train * Time taken by freight train

16 * 4 = x * 6

64 = 6x

x = 10.67 km/hr (approx)

Therefore, the average speed of the freight train was approximately 10.67 km/hr.

Now, let's go through each option and explain why it is right or wrong:

A. 40: This option is incorrect. The average speed of the freight train is approximately 10.67 km/hr, not 40 km/hr.

B. 30: This option is incorrect. The average speed of the freight train is approximately 10.67 km/hr, not 30 km/hr.

C. 80: This option is incorrect. The average speed of the freight train is approximately 10.67 km/hr, not 80 km/hr.

D. 60: This option is incorrect. The average speed of the freight train is approximately 10.67 km/hr, not 60 km/hr.

The Answer is: A. 40

In june a baseball team that played 60 games had won 30% of its game played. After a phenomenal winning streak this team raised its average to 50% .How many games must the team have won in a row to attain this average?
general knowledge math & puzzles

  1. 12

  2. 20

  3. 24

  4. 40

Show answer
Correct Option: C

Some green are blue. No blue are white.
general knowledge math & puzzles

  1. Some green are white

  2. No white are green

  3. No green are white

  4. None of the above

Show answer
Correct Option: A

If the word 'CODING' is represented as DPEJOH , then the word 'CURFEW' can be represented?
general knowledge math & puzzles

  1. DVSGFX

  2. DVSHFX

  3. DGSHFX

  4. DTSGFY

Show answer
Correct Option: A

If in a certain code 'RANGE' is coded as 12345 and 'RANDOM' is coded as 123678, then the code for the word 'MANGO' would be
general knowledge math & puzzles

  1. 82346

  2. 82543

  3. 84563

  4. 82357

Show answer
Correct Option: B

In a group of 15,7 have studied Latin, 8 have studied Greek, and 3 have not studied either.How many of these studied both Latin and Greek

general knowledge math & puzzles

  1. 2

  2. 3

  3. 4

  4. 5

Show answer
Correct Option: B

1, 3, 4, 8, 15, 27, __
general knowledge math & puzzles

  1. 30

  2. 40

  3. 50

  4. 60

Show answer
Correct Option: C

The square of a two digit number is divided by half the number. After 36 is added to the quotient, this sum is then divided by 2. The digits of the resulting number are the same as those in the original number, but they are in reverse order. The ten's place of the original number is equal to twice the difference between its digits. What is the number?
general knowledge math & puzzles

  1. 41

  2. 46

  3. 45

  4. 44

Show answer
Correct Option: B

If a and b are positive integers and (a-b)/3.5 = 4/7, then
general knowledge math & puzzles

  1. b = a

  2. b < a

  3. b > a

  4. b => a

Show answer
Correct Option: B
Explanation:

To solve this question, the user needs to know how to manipulate equations with variables and fractions.

We are given the equation:

$$(a-b)/3.5 = 4/7$$

We can simplify this equation by cross-multiplying and solving for a-b:

$$(a-b) = (4/7)*3.5$$

$$(a-b) = 2$$

Now, we have the equation a-b = 2, which means that a is two more than b. Therefore, b < a.

Option B is correct because b is always less than a in this equation.

Option A is incorrect because b is not equal to a.

Option C is incorrect because b is always less than a in this equation.

Option D is incorrect because b is always less than a in this equation.

The Answer is: B. b < a.