This study aims to analyze the revenue and efficiency of the coffee powder processing industry "Cap Jempol" in Rejang Lebong Regency. The research employs a quantitative descriptive approach, focusing on revenue analysis, cost structure, and efficiency levels. Data were collected through interviews, observations, and questionnaires distributed to business owners and workers in the industry. The analysis shows that the total revenue (TR) of the "Cap Jempol" coffee powder business is IDR 35,000,000 per month, with total costs (TC) amounting to IDR 21.229.542 per month. The resulting profit is IDR 13.770.458 per month, and the Revenue-Cost Ratio (R/C Ratio) is calculated at 1.65, indicating that the business is profitable and efficient. Furthermore, labor productivity is measured at 100 kg per worker per month, demonstrating an efficient production process. Several factors influencing business revenue include raw material costs, operational expenses, market demand, marketing strategies, and competition. The findings suggest that improving production efficiency, expanding market reach, and optimizing cost management could enhance business profitability.

This research aims to analyze the types of errors and factors that cause students' errors in solving plantation economics story questions. This research is a qualitative and quantitative descriptive research. The subjects in this research were students in the second semester of the Pat Petulai University Coffee Science Study Program for the 2023/2024 academic year, totaling 18 students. The instruments and data collection techniques used in this research were test sheets, interviews and questionnaires. The results of the research show that the types of errors made by students are (1) conceptual errors by 96.55% of students (2) calculation errors by 86.20% of students, (3) errors in reading questions by 89.65% of students, (4) strategic errors amounted to 79.31% of students (5) data usage errors amounted to 65.51% of students. Factors causing errors include poor understanding of concepts, weak mathematics skills, affective factors, less effective teaching methods.