Q: 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?
A: 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 is 84.

Q: Sophia ate 1/6 of her pie and she put the rest on the fridge. If the pie left in the fridge weighs 1200 grams, how many grams did Sophia eat?
A: If Sophia ate 1 / 6 of the pie, then 6 / 6 - 1 / 6 = 5 / 6 is left in the fridge. Let x be the pie's original weight. The current weight of the pie can be described by 5x / 6 = 1200 grams. So, 5x = 7200. And, the original weight is x = 1440 grams. So, Sophia ate 1440 grams original - 1200 grams after = 240 grams of pie. The answer is 240.

Q: John commissions an artist to make him a 9 by 13 drawing. A black and white drawing that size would cost $160. He wants a color drawing so that is 50% more expensive. How much did he pay?
A:
The extra cost for coloring is 160 * .5 = $80. So the total cost was 160 + 80 = $240. The answer is 240.