JKSSB Laboratory Attendant 2026 Paper

Explanation

The correct option is: Both (A) and (R) are true, but (R) is NOT the correct explanation of (A)

Explanation

The correct option is: Both (A) and (R) are true, but (R) is NOT the correct explanation of (A)

Explanation

True

Explanation

Step 1: Calculate the total distance to be covered

When two trains cross each other completely, the total distance they need to cover is equal to the sum of their individual lengths.

• Length of Train 1 ($L_1$) = $120 \text{ m}$

• Length of Train 2 ($L_2$) = $180 \text{ m}$

  $$\text{Total Distance} = L_1 + L_2 = 120 + 180 = 300 \text{ m}$$

Step 2: Calculate the relative speed

Since the two trains are moving in opposite directions, their speeds are added up to find the relative speed.

• Speed of Train 1 = $54 \text{ km/h}$

• Speed of Train 2 = $72 \text{ km/h}$

  $$\text{Relative Speed} = 54 + 72 = 126 \text{ km/h}$$

Step 3: Convert the relative speed into metres per second (m/s)

Since the distance is in metres, we need the speed to be in $\text{m/s}$. To convert $\text{km/h}$ to $\text{m/s}$, multiply by $\frac{5}{18}$:

$$\text{Relative Speed in m/s} = 126 \times \frac{5}{18}$$

$$\text{Relative Speed in m/s} = 7 \times 5 = 35 \text{ m/s}$$

Step 4: Calculate the time taken

Using the time, speed, and distance formula:

$$\text{Time} = \frac{\text{Total Distance}}{\text{Relative Speed}}$$

$$\text{Time} = \frac{300}{35} = \frac{60}{7} \text{ seconds}$$

$$\text{Time} \approx 8.57 \text{ seconds} \text{ (or } 8\frac{4}{7} \text{ seconds)}$$

The two trains will take $8.57$ seconds (or $\frac{60}{7}$ seconds) to completely cross each other.

Explanation

Since the distance remains constant, speed and time are inversely proportional to each other ($\text{Speed} \propto \frac{1}{\text{Time}}$).

1. Find the Speed Ratio:

   An increase of $25\%$ means if the original speed was $100\%$, the new speed is $125\%$.

   $$\text{Ratio of Speed (Original : New)} = 100 : 125 = 4 : 5$$

2. Find the Time Ratio:

   Since time is inversely proportional to speed, we flip the ratio:

   $$\text{Ratio of Time (Original : New)} = 5 : 4$$

3. Calculate the Original Time:

   The difference between the original time and the new time in the ratio is $5 - 4 = 1 \text{ unit}$.

   According to the question, this $1 \text{ unit}$ difference is equal to $1 \text{ hour}$.

   $$\text{Original Time} = 5 \text{ units} = 5 \times 1 \text{ hour} = \mathbf{5 \text{ hours}}$$

Explanation

1. Substitute the values into the formula:

   $$\text{Average Speed} = \frac{2 \times 50 \times 40}{50 + 40}$$

2. Simplify the numerator and denominator:

   $$\text{Average Speed} = \frac{4000}{90}$$

3. Calculate the final value:

   $$\text{Average Speed} = \frac{400}{9} \approx 44.44 \text{ km/h}$$

The average speed for the whole journey is $44.44 \text{ km/h}$ (or $44\frac{4}{9} \text{ km/h}$).

Explanation

True

Explanation

The correct option is that Both I and II are possible causes for the sharp increase in online education platforms.

Here is the breakdown of why both statements act as immediate and valid causes:

• Cause I (Affordable internet availability): This provides the necessary technological infrastructure. Without cheap and widespread internet access, the general public would not be able to stream lectures or access digital course materials, meaning platforms could not grow on a large scale.

• Cause II (Increased demand for flexible learning): This provides the market demand. Working professionals, students in remote areas, and individuals looking to upskill require learning options that fit their own schedules, driving the growth of these platforms.

Explanation

• "My mother-in-law": This refers to the mother of Raj's wife.

• "The only son of my mother-in-law": The only son of Raj's mother-in-law would be his wife's brother (Raj's brother-in-law).

• "She is the wife of [this only son]": The wife of Raj's brother-in-law is Raj's sister-in-law (specifically, his wife's brother's wife).

Explanation

1. $P - Q$ * According to "$A - B$", this means $P$ is the brother of $Q$.

   • (So, $P$ is male and they belong to the same generation).

2. $Q \times R$ * According to "$A \times B$", this means $Q$ is the father of $R$.

   • (So, $Q$ is male and belongs to the generation above $R$).

3. $R + S$ * According to "$A + B$", this means $R$ is the mother of $S$.

   • (So, $R$ is female and belongs to the generation above $S$).

Putting It All Together (Family Tree Analysis):

• $P$ and $Q$ are brothers.

• $Q$ has a child named $R$ (specifically, $R$ is $Q$'s daughter because $R$ is the mother of $S$).

• Since $P$ is the brother of $R$'s father ($Q$), $P$ is the paternal uncle of $R$.

• $R$ has a child named $S$, making $Q$ the grandfather and $P$ the paternal grand-uncle of $S$.

Conclusion:

The expression $P - Q \times R + S$ establishes the following primary relationships:

• $P$ is the paternal uncle of $R$ (Father's brother).

• $P$ is the paternal grand-uncle of $S$.

• $R$ is the niece of $P$.