Perbandingan Senilai Dan Berbalik Nilai

Explanation
The scale of a map is the ratio of the distance on the map to the actual distance on the ground. In this case, the actual distance between the two cities is 80 km, while the distance on the map is 5 cm. To find the scale, we divide the actual distance by the distance on the map. So, 80 km divided by 5 cm is equal to 16,000,000. Therefore, the scale of the map is 1:1,600,000.

Explanation
The car requires 15 liters of gasoline to cover a distance of 180 km. If the car's tank contains 20 liters of gasoline, we can calculate the distance it can cover by using a proportion. We set up the proportion: 15 liters is to 180 km as 20 liters is to x km. We can cross-multiply and solve for x. By doing so, we find that x is equal to (20 liters * 180 km) / 15 liters, which simplifies to 240 km. Therefore, the car can cover a distance of 240 km with a full tank of gasoline.

Explanation
The given information states that a job can be completed by 15 workers in 12 weeks. If the job needs to be finished in 9 weeks, it means that the time available is reduced. To compensate for this, more workers are required to maintain the same level of productivity. Therefore, the correct answer is 5 orang, as adding 5 more workers will help complete the job in the shorter time frame.

Explanation
The distance traveled by the wheel is directly proportional to the number of rotations. In this case, we can set up a proportion: 18 rotations is to 27 meters as 12 rotations is to x meters. Solving for x, we find that x is equal to 18 meters. Therefore, when the wheel rotates 12 times, it will travel a distance of 18 meters.

Explanation
When there are 30 occupants, the food supply is estimated to last for 8 days. This means that each person consumes 1/8 of the total food supply per day. When there is an additional 10 occupants, the total number of occupants becomes 40. Since the rate of consumption per person remains the same, the food supply will now last for 6 days (1/8 of the total food supply per day multiplied by 40 occupants). Therefore, the correct answer is 6 days.

Explanation
Dalam waktu 7 menit, Deni mampu membaca 140 kata. Untuk membaca 700 kata, kita dapat menggunakan perbandingan bahwa dalam 7 menit Deni membaca 140 kata. Jika kita ingin tahu berapa waktu yang diperlukan untuk membaca 700 kata, kita dapat mengalikan 7 dengan 10, karena 140 x 10 = 1400, yang merupakan 10 kali lipat dari 140. Oleh karena itu, waktu yang diperlukan untuk membaca 700 kata adalah 10 x 7 menit = 70 menit.

Explanation
The given question states that a vehicle takes 3 hours and 20 minutes to travel a certain distance at an average speed of 90 km/h. The question then asks for the time it would take to travel the same distance at an average speed of 80 km/h. Since the distance remains the same, a lower speed would result in a longer travel time. Therefore, the correct answer is 3 hours and 45 minutes, which is longer than the initial time of 3 hours and 20 minutes.