Explanation

Kublai Khan was the Emperor of China.

He was the founder of the Yuan Dynasty (1271–1368).

He was the grandson of Genghis Khan.

He played a significant role in the Mongol expansion and the establishment of Mongol rule in China.

Explanation

PTC stands for Primary Teaching Certificate.

It is a qualification for teaching at the primary school level.

It is typically awarded after completing training to teach in primary schools.

Explanation

To find the average speed:

Total distance = 120 km * 2 (to and fro) = 240 km

Time taken to go = 120 km / 60 km/h = 2 hours

Time taken to return = 120 km / 40 km/h = 3 hours

Total time = 2 + 3 = 5 hours

Average speed = Total distance / Total time

= 240 km / 5 hours

= 48 km/h

Explanation

Given xy = 1 and x > 0:

y = 1/x

We want to minimize x + y = x + 1/x.

Let's find the minimum value:

Let f(x) = x + 1/x

f'(x) = 1 - 1/x² = 0 for minimum

x² = 1

x = 1 (since x > 0)

f(1) = 1 + 1/1 = 2

The minimum value of x + y is 2.

Explanation

Given that 3 women = 2 men in terms of work:

Work done by 15 men in 1 hour = 1 / (21 * 8)

Work done by 1 man in 1 hour = 1 / (15 * 21 * 8)

Work done by 1 woman in 1 hour = (2/3) * (1 / (15 * 21 * 8))

Work done by 21 women in 1 hour = 21 * (2/3) * (1 / (15 * 21 * 8))

= 14 / (15 * 21 * 8)

= 1 / (15 * 9 * 8) (simplified for 21 women working)

If 21 women work for 6 hours a day:

Work done by 21 women in 1 day = 6 * (1 / (15 * 9 * 8)) * (15 * 9)

= 6 / 8

To complete the work:

Number of days = 8 / 6 * 21

= 28

None of the given options directly match the calculation approach provided, but recalculating properly considering the work equivalence and hours:

15 men * 21 days * 8 hours = 2520 man-hours

Given 3 women = 2 men, 21 women = 14 men equivalent

Let x be the number of days for 21 women working 6 hours/day:

14 men * x days * 6 hours = 2520 man-hours

84x = 2520

x = 30

Explanation

Misspelled means غلط ہجے

Explanation

The correct sentence is: People call this place the Forbidden Forest.

"Call" is used when naming or referring to something by a specific title.

Explanation

The student will go camping during the vacation.

طالب علم چھٹی کے دوران کیمپنگ میں جائے گا۔

During is a preposition. 

It is used throughout the duration of (a period of time). 

By indication of "period of time throughout students vacation", we marked the option "during".

Explanation

A circuit is a closed path through which electrons (electric current) flow.

It typically includes components like resistors, batteries, and wires, allowing controlled movement of current.

Explanation

Petroleum has the highest energy density among fossil fuels, making it the richest source of energy.

It is widely used in transportation, industry, and power generation due to its high calorific value.