Explanation

Insulators are materials that resist the flow of heat (and also electricity), such as wood, rubber, or plastic.

They are used to prevent heat loss or protect from heat transfer.

Explanation

13 + 12 = 25 is mathematically correct.

Explanation

P(A) is the power set of A = {1, 2}, which includes all subsets: ∅, {1}, {2}, {1, 2}.

So, {2} is one of the subsets, hence it is an element of P(A).

Explanation

The area of a trapezium is given by:

Area = (1/2) × (sum of bases) × altitude

Given:

Area = 153 m^2

Altitude = 9 m

One base = 13 m

Let's denote the other base as 'b'. Then:

153 = (1/2) × (13 + b) × 9

Multiply both sides by 2:

306 = (13 + b) × 9

Divide both sides by 9:

34 = 13 + b

Subtract 13 from both sides:

b = 21

Explanation

Given:

x + 1/x = 10

Squaring both sides:

(x + 1/x)^2 = 10^2

x^2 + 2(x)(1/x) + 1/x^2 = 100

x^2 + 2 + 1/x^2 = 100

Subtract 2 from both sides:

x^2 + 1/x^2 = 98

Explanation

Cost per student: 1 3/8 = 11/8

Total amount: 13 3/4 = 55/4

Now, divide the total amount by the cost per student:

Number of students = Total amount ÷ Cost per student

= (55/4) ÷ (11/8)

= (55/4) × (8/11)

= 55 × 2 / 11

= 110 / 11

= 10

Explanation

The Olympic Games have an long history. According to the tradition, they first took place at Olympia in ancient Greece. Every four years for more then a thousand years, the Greeks held these games in honor of the god Zeus. Then in 394 A.D., the games were abolish by Emperor Theodosius I of Rome. The Olympic Games were re-established many centuries later in 1896. The first modern Olympic Games were held, appropriately enough to Athens and Greece. Every four years since then accept during World War I and II, the games were held in various parts of the world.

1. According to the tradition, they first had taken place at Olympia on ancient Greece.

In

2. Every four years for ______ a thousand years, the Greeks held these games in honor of the god Zeus.

More than

3. Then in 394 A.D, the games were _____ by Emperor Theodosius I of Rome.

Abolished

4. The Olympic Games _____ many centuries later in 1896.

Were re-established

5. Every four years since then _____ during World War I and II, the games were held in various parts of the world.

Except

Explanation

To find the length of marks on dust when the wheel completes one rotation, we need to calculate the circumference of the wheel:

Circumference = π × diameter

= π × 35 cm

≈ 3.14 × 35 cm

≈ 109.9 cm

Rounding to the nearest whole number:

≈ 110 cm

Explanation

Reactants are the elements or compounds that undergo a chemical reaction to form new substances.

They are present before the reaction begins and are transformed into products.

Explanation

Passage

When we eat dirty food, the germs get into our body and cause illness. So we should always remember not to eat food if flies are sitting or walking on it. Malaria, Typhoid, Cholera and many other diseases are caused by these germs. Dust, standing water, dirty and rotten things are breeding places for germs. For example, Malaria is carried by one of the mosquitoes. If a person has Malaria and a mosquito bites him, it carries away some of the germs of that disease.

When this mosquito bites a healthy person, the germs may get into the blood and may cause Malaria. Mosquitoes lay their eggs in standing water and cause Cholera. The most important element for our health and life is to keep ourselves and our foodstuffs clean. If we keep ourselves, our house and surroundings clean, there are least chances of our being infected by the germs. Cleanliness can protect us from our enemies i.e. germs. Cleanliness can play a major role to save us from germs and many diseases.

1. Source of germs is ______?

Dirt

2. Diseases caused by germs are _______?

Typhoid, Cholera

3. What are breeding places for germs?

Dust, standing water, dirty and rotten things

4. Malaria is caused by _____?

Mosquitoes

5. Mosquitoes lay their eggs in _____?

Standing water