Chemists commonly create a solution by mixing two products of differing concentrations together. Find the amount of $\sage {concA}\%$ acid solution and $\sage {concB}\%$ acid solution needed to create a $\sage {totalVolume}$ liter $\sage {concTotal}$% solution.

$\sage {concA}\%$ acid solution: $\answer [tolerance=0.05]{\sage {volumeA}}$ liters

$\sage {concB}\%$ acid solution: $\answer [tolerance=0.05]{\sage {volumeB}}$ liters

There is initially $\sage {initialAmount2}$ grams of element $X$. The half-life of element $X$ is $\sage {halfLifeYears2}$ years. How much element $X$ will be left after $\sage {afterYears}$ years?

$\answer [tolerance=0.01]{\sage {amountLeft}}$ grams

A company sells doughnuts. They incur a fixed cost of $$\sage {fixedCost1}$ for rent, insurance, and other expenses. It costs $$\sage {productionCost1}$ to produce each doughnut. The company sells each doughnut for $$\sage {sellingPoint1}$. How many doughnuts would they need to sell to break even?

$\answer {\sage {breakEven}}$ doughnuts

Kepler’s Third Law: The square of the time, $T$, required for a planet to orbit the Sun is directly proportional to the cube of the mean distance, $a$, that the planet is from the Sun. Assume that Neptune’s mean distance from the Sun is $\sage {a1}$ AUs and it takes Neptune about $\sage {T1}$ months to orbit the Sun. If it takes Saturn about $\sage {saturnMonths}$ months to orbit the Sun, what is Saturn’s mean distance from the Sun?

$\answer [tolerance=0.05]{\sage {saturnA}}$

The half-life of carbon-14 is 5,730 years. A bone fragment is found that contains $\sage {percent3}\%$ of its original carbon-14. To the nearest year, how old is the bone?

$\answer {\sage {old3}} \, \text { years old}$

Two UFPD are patrolling the campus on foot. To cover more ground, they split up and begin walking in different directions. Office A is walking at $\sage {officerAspeed3}$ mph directly south while Office B is walking at $\sage {officerBspeed3}$ mph directly west. How long would they need to walk before they are $\sage {distanceOfficers}$ miles away from each other?

$\answer [tolerance=0.05]{\sage {timeOfficers}}$ minutes

A population of bacteria $\sage {rate1}$ every hour. If the culture started with $\sage {initialBacteria1}$, how long would it take before the population is over $\sage {hugeBacteriaPopulation}$ million?

$\answer [tolerance=0.05]{\sage {timeToHugePopulation}}$ hours