A fixer uses 30% of the nails in a container to repair the kitchen. He also used 70% of the remaining nails in the container to repair the fence. If there were 400 nails in the container, how many nails are remaining? Let's be accurate as possible.
The fixer used 30 / 100 * 400 = 120 nails to fix the kitchen. The number of nails remaining in the container after he fixes the kitchen is 400 - 120 = 280. He also uses 70 / 100 * 280 = 196 of the nails remaining in the container to fix the fence. The total number of nails which the fixer hasn't used is 280 - 196 = 84.
The answer: 84.