Latihan US Matematika Kelas Ix

Explanation
When the power goes out, the temperature inside the refrigerator increases by 2°C per minute. After 15 minutes without power, the temperature would increase by 2°C x 15 minutes = 30°C. Therefore, the new temperature inside the refrigerator would be the initial temperature of -5°C + 30°C = 25°C.

Explanation
The given information states that a job can be completed in 28 days by 12 workers. However, after 16 days, the work is stopped for 4 days. To ensure that the job is completed on time, additional workers are needed. Since the work has already been ongoing for 16 days, only 12 days are left to complete the job. To calculate the number of additional workers needed, we can use the formula: (number of workers * number of days) / (total days - days already worked). Plugging in the values, we get (12 * 12) / (28 - 16) = 144 / 12 = 12. Therefore, 12 additional workers are needed.

Explanation
The given expression can be simplified using the order of operations (PEMDAS/BODMAS). First, we calculate the value inside the parentheses: -25 x (8 + (-9)) = -25 x (-1) = 25. Then, we calculate the value inside the second set of parentheses: (2 - 7) = -5. Finally, we divide 25 by -5, which gives us -5. Therefore, the correct answer is -5.

Explanation
The price of 1 kodi of fabric is Rp. 300,000. To find the price of 10 helai of fabric, we need to divide the price of 1 kodi by the number of helai in 1 kodi, which is 12. Therefore, the price of 10 helai of fabric is Rp. 300,000 / 12 = Rp. 25,000. However, none of the given options match this calculation. Therefore, the correct answer is not available.

Explanation
The correct answer is 32 because when we divide 163 by 4, we get 40.75. When we multiply 40.75 by 82, we get 3345.5. Finally, when we divide 3345.5 by 3, we get 1115.1667. Rounding this to the nearest whole number, we get 1115. Therefore, the result of the given expression is 32.

Explanation
The given expression can be simplified step by step as follows:
1. 5 x (21 + (-7)) : ((-13)-(-8))
2. 5 x (21 - 7) : (-13 + 8)
3. 5 x 14 : (-5)
4. 70 : (-5)
5. -14

Therefore, the correct answer is -14.

Explanation
The bacteria double in number every minute, so if there are 4 bacteria in the second minute, there would be 8 in the third minute, 16 in the fourth minute, and so on. By the seventh minute, the bacteria would have doubled 6 times, resulting in 4 x 2^6 = 128 bacteria.

Explanation
The total number of students who enjoy playing basketball or volleyball is the sum of students who enjoy playing basketball (40) and students who enjoy playing volleyball (28). However, since there are 10 students who enjoy playing both sports, they are counted twice in the previous sum. To find the total number of students in the group, we subtract the 10 students who enjoy both sports from the sum of students who enjoy playing basketball or volleyball. This gives us 40 + 28 - 10 = 58. Therefore, the correct answer is 58.

Explanation
The diagram shows the sales of cars at a dealership. To find the difference in sales between February and June, we need to subtract the number of cars sold in February from the number of cars sold in June. The difference is 12 units, indicating that 12 more cars were sold in June compared to February.

Explanation
The comparison ratio between Ani and Ina's money is 3:5. This means that for every 3 units of money that Ani has, Ina has 5 units. The total amount of money they have is Rp. 400,000. To find the difference between their money, we need to find the difference between 5 units and 3 units. The difference is 2 units. Since 1 unit is equal to Rp. 400,000 divided by 8 (3+5), which is Rp. 50,000, the difference between their money is 2 units multiplied by Rp. 50,000, which equals Rp. 100,000.