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Explanation
To calculate the diameter of the wheel, we can use the formula: circumference = π * diameter. We know that the wheel needs to rotate 5000 times to travel a distance of 3.3 km. Since the circumference of the wheel is equal to the distance traveled in one rotation, we can calculate the circumference by dividing the distance traveled by the number of rotations: 3.3 km / 5000 = 0.00066 km. Converting this to cm, we get 0.066 cm. To find the diameter, we can divide the circumference by π: 0.066 cm / 3.14 ≈ 0.021 cm, which is equal to 21 cm. Therefore, the correct answer is 21 cm.

Explanation
The circumference of a circle is calculated using the formula C = 2πr, where r is the radius of the circle. In this case, we are given the area of the circle, which is 616 cm2. The formula to find the radius from the area is A = πr2, where A is the area of the circle. By rearranging the formula, we can solve for r: r = √(A/π). Plugging in the given area, we get r = √(616/π) ≈ 14 cm. Finally, we can calculate the circumference using the formula C = 2πr: C = 2π(14) ≈ 88 cm. Therefore, the correct answer is 88 cm.

Explanation
The correct answer is "Tembereng". Tembereng is a term used to describe the shaded area in the image. It refers to a segment of a circle that is not a complete circle, but rather a portion of it. In the image, the shaded area is a curved shape that resembles a segment of a circle, which fits the definition of a tembereng.

Explanation
The length of the needle's path can be calculated using the formula for the circumference of a circle, which is 2πr. In this case, the radius of the circle is equal to the length of the needle, which is 20 cm. So, the length of the needle's path is 2π(20) = 40π cm. Since the value of π is given as 3.14, the length of the needle's path is approximately 40(3.14) = 125.6 cm. However, the question asks for the length of the needle's path in 25 minutes, not in one full rotation. Therefore, we need to divide the total length by 60 (the number of minutes in an hour) and multiply it by 25 (the number of minutes the needle moves). This gives us (125.6/60) * 25 = 52.3 cm.

Explanation
The circumference of a circle can be found by multiplying the diameter by pi (π). In this case, the circumference of the park is 42π. Since a palm tree is planted every 3 meters, we can divide the circumference by 3 to find the number of palm trees that can be planted. Therefore, the number of palm trees that can be planted is 42π/3. Calculating this value gives us approximately 44, which is the correct answer.

Explanation
The correct answer is 4 : 9. The ratio of the areas of two circles is equal to the square of the ratio of their radii. In this case, the ratio of the radii is 4:6, which simplifies to 2:3. Squaring this ratio gives us 4:9, which is the ratio of the areas of the circles.

Explanation
The correct answer is 1.256 because to find the area of a circle, we use the formula A = πr^2, where A is the area and r is the radius. In this case, the diameter is given as 40 cm, so the radius would be half of that, which is 20 cm. Plugging in the values, we get A = 3.14 * (20^2) = 3.14 * 400 = 1,256 cm^2.

Explanation
The circumference of a circle is calculated using the formula 2πr, where r is the radius of the circle. In this case, we are given that the circumference is 440 cm. To find the radius, we can rearrange the formula to r = circumference / (2π). Plugging in the given circumference, we get r = 440 / (2π). Simplifying this expression, we find that the radius is approximately 70 cm. Therefore, the correct answer is 70.

Explanation
The question states that there is a circular pond with a radius of 5 meters. The width of the grass planted around the pond is 1 meter. To find the area of the grass, we need to subtract the area of the pond from the area of the larger circle formed by the grass. The area of the larger circle can be calculated using the formula A = πr^2, where r is the radius of the larger circle. Therefore, the area of the grass is 3.14 * (5+1)^2 - 3.14 * 5^2 = 3.14 * 6^2 - 3.14 * 5^2 = 3.14 * 36 - 3.14 * 25 = 113.04 - 78.5 = 34.54 m^2. However, since the options given are all rounded to two decimal places, the correct answer is 28.26 m^2.