Question

For a science experiment Marcia dissolved 1.0 kilogram of salt in 3.0 liters of water. For a different experiment, Bobby dissolved 3.0 pounds of salt in 10.0 pints of water. Which person made a more concentrated salt solution? Complete the explanation. Use 1 kg = 2.2 lb and 1 L = 2.11 pints. Round your answers to the nearest hundredth.

Answer 1

Answer: Marcia made a more concentrated salt solution.

Explanation:

Marcia used 1 kg of salt, which the exercise tells us is 2.2 lb.

She dissolved it in 3L of water, so we have to find out how much that is in pints. We do that using cross multiplication.

If 1L equals 2.11 pints, then

xpints / 3L = 2.11pints / 1L, so

xpints = (3L . 2.11pints) / 1L = 6.33 pints

Now we know she dissolved 2.2lb in 6.33 pints of water. We use cross multiplication again to find out how much salt she would have in 10 pints, so we can know how concentrated it is compared to Bobby's solution, which is 10 pints.

xlb / 10pints = 2.2lb / 6.33pints

xlb = (10pints . 2.2lb) / 6.33pints = 3.47lb

So Marcia has a concentration of 3.47lb per 10 pints, whereas Bobby only has 3lb per 10 pints.