8. The percentage of salt in each mixture is 0.35%.
To find out the latter part of the problem, we can use algebra:
14 (grams of salt) = 0.35m (0.35% of the mixture)
14 ÷ 0.35 = 0.35m ÷ 0.35 (we want to find just m, so we have to divide it by 0.35)
40 = m. The scientist made 40 g of mixture!
9. We just divide 32.5 pounds by 0.25 ( a quarter).
32.5 ÷ 0.25 = 130 kids!
10. Her original distance is 0.5 miles. But! She walked back 0.25 (quarter) mile so now this adds a quarter of a mile of distance from her house to her school.
0.5 × 3 = 1.5 + 0.25 = 1.75 miles from her house to her school.
