Question bank: Percentage: Conversion with Fractions and Decimals

One of the biggest challenges of environmental sustainability is raising awareness about the rational use of water. According to a survey conducted in a community, the daily water consumption per person decreased from 120 liters to 96 liters after an educational campaign. Considering the initial consumption as 100% reference, what was the percentage reduction in daily water consumption per person in this community? And if this consumption were expressed as a fraction, what would be the fraction corresponding to the percentage reduction? Additionally, knowing that the percentage reduction can be represented by a decimal number, what would be the exact decimal value that expresses this reduction?

In an organic vegetable garden, the production of lettuce in the last year was 350 kilograms. To meet sustainability guidelines, the producer decides that 60% of this weight should be destined for sale at local markets, while the rest will be used for family consumption and donation to a charity. If the lettuce is sold exclusively in 0.5 kg packages, how many packages will the producer be able to prepare with the portion destined for sale?

In a laboratory experiment, a liquid was spilled into a container in the shape of a right prism with a square base. The base of the prism has 3 cm on each side and the height of the prism is 10 cm. After the spill, it was found that the liquid covered 60% of the total height of the prism. What is the amount of liquid, in cubic centimeters, that was spilled into the container? Consider the volume of a right prism as the base area multiplied by the height and that 60% of 10 cm is equal to 6 cm.

A technology company has hired a new cloud storage service that offers 5 GB for free and charges R$ 0.10 for each additional GB. After a period of use, an employee noticed that the amount of data stored in the cloud was 7.8 GB. Considering that the company wants to optimize costs, the finance department requested the conversion of the amount of data stored into a percentage of the total available space. Calculate the percentage of the amount of data stored in relation to the total space and explain how understanding this percentage can help the company make decisions about the use of the cloud storage service.

During an interdisciplinary project in Geography and Science, 7th-grade students investigated the atmospheric composition in the region where they live. They collected data on the concentration of carbon dioxide (CO2) in parts per million (ppm) and compared it with international standards that highlight the issue of global warming. After collecting and analyzing the data, the students observed that the concentration of CO2 in the local atmosphere had increased by 0.015% compared to the previous year. Considering the initial concentration of CO2 in the local atmosphere was 380 ppm, what was the absolute increase, in parts per million, of the CO2 concentration?