Mathematics for IGCSE & O level - Proportion (Section 2 - No. 27)
The number of bricks needed to build a wall is inversely proportional to the number of workers. If it takes 8 workers 10 days to build a wall, how many days will it take 4 workers to build a wall?
5 days
10 days
16 days
20 days
解释
Days = k/workers; 10=k/8; k=80; Therefore, days = 80/4 = 20 days