Explanation

To evaluate this expression, we need to follow the order of operations (PEMDAS):

1. Subtract 13 from 4: 4 - 13 = -9

2. Subtract 5 from -9: -9 - 5 = -14

3. Add 8 to -14: -14 + 8 = -6

4. Add 4 to -6 (since -(-4) = 4): -6 + 4 = -2

5. Divide 15 by 3: 15 ÷ 3 = 5

6. Subtract 5 from -2: -2 - 5 = -7

So, the final answer is: -7

Explanation

Newton's Third Law of Motion states: "For every action, there is an equal and opposite reaction."

From this law, we can infer:

1. Statement 1: For every interaction, there is a pair of forces acting on the two interacting objects. (TRUE)
2. Statement 2: The magnitude of the force on the first object equals the magnitude of the force on the second object. (TRUE)
3. Statement 3: Forces always come in pairs - equal and opposite action-reaction force pairs. (TRUE)
4. Statement 4: Action and its reaction act on two same bodies. (FALSE - Action and reaction forces act on different bodies)
5. Statement 5: Action and its reaction act on two different bodies. (TRUE)

So, all statements except Statement 4 can be inferred from Newton's Third Law of Motion.

Explanation

NPT stands for Non-Proliferation Treaty

NPT signed: 1968

not a member of the NPT:

• India,
• Israel,
• North Korea,
• Pakistan 
•  South Sudan 

members of the five NPT nuclear-weapon states:

• China
• France
  
• Russia
• The United States
• The United Kingdom

Languages:

• English
• Russian
  
• French
• Spanish
• Chinese

Parties: 190 (complete list)

Iran threatened to withdraw from the Treaty on the NPT 

Explanation

The pattern of the sequence appears to be an alternating addition of 9 and 2:

12 + 9 = 21

21 + 2 = 23

23 + 9 = 32

32 + 2 = 34

34 + 9 = 43

So, the missing number is: 43

Explanation

Clear nights are cooler than cloudy nights because of radiation. Here's why:

• On a clear night, the Earth's surface rapidly loses heat by radiating it into space, a process known as radiative heat loss. This causes the temperature to drop.
• On a cloudy night, the clouds act as an insulating blanket, trapping heat and preventing it from escaping into space. This reduces radiative heat loss and keeps the temperature warmer.

Explanation

I will give you your present after you eat your dinner.

A complex sentence contains one independent clause and at least one dependent clause. 

Here, "I will give you your present" is the independent clause, and "after you eat your dinner" is the dependent clause.

Explanation

The last day's play between Pakistan and Australia was disrupted by rain.

Given sentence is in simple past tense and it is in active voice.

Rule :

Subject + (was / were) + V3 + Optional Agents.

Explanation

The sun is visible a little before it rises and a little after it sets because of atmospheric refraction.

Refraction is the phenomenon that occurs when light changes direction as it passes from one transparent medium to another.

Explanation

In indirect speech, "Need I" changes to "if he had to," and "this chapter" becomes "that chapter" for proper tense and reported speech structure.

Explanation

Total distance covered by both trains = 1160 + 1160 = 2320 meters

Time taken to cross each other = 20 seconds

Relative speed (combined speed of both trains) = Total distance / Time = 2320 / 20 = 116 meters/second

Since both trains have the same speed, the speed of each train = Relative speed / 2 = 116 / 2 = 58 meters/second

Convert meters/second to km/second: 58 / 1000 = 0.058 km/second (approximately)

Convert km/second to km/hour: 0.058 * 3600 = 208.8 km/hour