One of the essential minerals in the human body is salt. How much salt (NaCl) is in the average adult human body?
A. 1 kg B. 250 grams C. 500 grams D. practicially none ANSWER: B
What formula indicates that the pK of an acid is numerically equal to the pH of the solution when the molar concentration of the acid and its conjugate base are equal?
A. Michaelis-Menten equation B. Haldanes equation C. Henderson-Hasselbalch equation D. Hardy-Windberg law Answer: Option C
A growers’ cooperative has a farmer’s market in the town center every Saturday. They sell what they have grown and split the money into several categories. 8.5% of all the money taken in is set aside for sales tax. $150 goes to pay the rent on the space they occupy. What remains is split evenly between the seven growers. How much total money is taken in if each grower receives a $175 share?
Let’s translate the text above into an equation. The unknown is going to be the total money taken in dollars. We’ll call this x. “8.5% of all the money taken in is set aside for sales tax." This means that 91.5% of the money remains. This is 0.915x. “$150 goes to pay the rent on the space they occupy.” This means that what’s left is 0.915x−150. “What remains is split evenly between the 7 growers.” That means each grower gets 0.915x−1507. If each grower’s share is $175, then our equation to find x is 0.915x−1507=175. First we multiply both sides by 7 to get 0.915x−150=1225. Then add 150 to both sides to get 0.915x=1375. Finally divide by 0.915 to get x≈1502.7322. Since we want our answer in dollars and cents, we round to two decimal places, or $1502.73. The workers take in a total of $1502.73.