Persamaan Dan Pertidaksamaan Linear Satu Variabel (Perbandingan) (Kls.7)

Explanation
The comparison of 2 dozens (2 lusin) to 96 pieces is 1:4. This means that for every 2 dozens, there are 4 times as many pieces. In other words, if you have 2 dozens, you would have 48 pieces. Therefore, the correct answer is 1:4.

Explanation
The given question states that the ratio a : 7 is equivalent to the ratio 36 : 84. To find the value of a, we can set up a proportion using the given ratios. Cross-multiplying, we get 84a = 36 * 7. Simplifying further, we find that 84a = 252, and dividing both sides by 84, we get a = 3. Therefore, the correct value of a is 3.

Explanation
The original photo has dimensions of 4 cm x 6 cm, which gives it an area of 24 cm². When the photo is enlarged by a factor of 5, the new dimensions become 20 cm x 30 cm, resulting in a new area of 600 cm². The ratio of the original area to the enlarged area is therefore 24 cm² : 600 cm², which simplifies to 1 : 25.

Explanation
The given question states that the ratio of Wahyu's money to Wisnu's money is 3:5. Since the amount of Wahyu's money is given as Rp. 630,000, we can calculate the amount of Wisnu's money by multiplying the ratio with the given amount.

3/5 * Rp. 630,000 = Rp. 1,050,000

Therefore, the correct answer is Rp. 1,050,000.

Explanation
Dalam pertanyaan ini, diketahui bahwa 90 roti diperlukan untuk menjamu 240 orang. Oleh karena itu, dapat diasumsikan bahwa setiap roti dapat digunakan untuk menjamu 240/90 = 2,67 orang. Jika hanya tersedia 120 roti, maka dapat dihitung bahwa jumlah orang yang dapat dijamu adalah 120 x 2,67 = 320 orang.

Explanation
If a job can be completed by 15 people in 2 weeks, it means that the total work required is equivalent to 15 x 2 = 30 person-weeks. To complete the same job in 10 days, which is equivalent to 10/7 = 1.43 weeks, we need to calculate the total work required as 30 person-weeks / 1.43 weeks = 20.98 person-weeks. Since we cannot have a fraction of a person, we round up to the nearest whole number, which is 21. Therefore, the additional number of workers needed is 21 - 15 = 6 people.

Explanation
16 siswa dibutuhkan untuk mengerjakan soal-soal tersebut dalam waktu 1 jam. Hal ini karena 16 siswa dapat menyelesaikan 640 soal dalam waktu 2 jam. Jika waktu yang tersedia hanya 1 jam, maka jumlah siswa yang dibutuhkan tetap sama yaitu 16 siswa.

Explanation
The scale of the map is given as 1:75,000. This means that 1 unit on the map represents 75,000 units in reality. The distance between city A and city B is 3.9 km. To find the distance on the map, we divide the actual distance by the scale factor: 3.9 km / 75,000 = 0.000052 km. Since 1 cm on the map represents 0.000052 km, we can multiply the distance on the map by 100,000 to convert it to centimeters: 0.000052 km * 100,000 = 5.2 cm. Therefore, the distance between city A and city B on the map is 5.2 cm.

Explanation
The scale of the map is 8 cm representing 96 km. To find the distance on the map, we can set up a proportion: 8 cm/96 km = x cm/168 km. Cross-multiplying, we get 96x = 8 * 168. Solving for x, we find x = 14 cm. Therefore, the distance on the map is 14 cm.

Explanation
The scale of the map is 1:1,800,000, which means that 1 cm on the map represents 1,800,000 cm in real life. The distance between the two cities on the map is 10.25 cm. To find the actual distance, we multiply 10.25 cm by 1,800,000 cm, which equals 18,525,000 cm. Converting this to kilometers, we divide by 100,000 (since there are 100,000 cm in a kilometer), resulting in 184.5 km. Therefore, the correct answer is 184.5 km.