Jett bought a cow from the market at $600 and took it to his farm. He spent $20 every day to buy food. He also used $500 to vaccinate and deworm the cow. If he sold the cow for $2500 after 40 days, calculate the profit he made from selling back the cow to the market. Give the rationale and then the answer.
Let's think step by step. The total cost of food that the cow ate for the forty days is 40 * $20 = $800. To feed and maintain the health of the cow, the total expenses Jett used is $500 + $800 = $1300. With the expenses, Jett used $1300 + $600 = $1900 on the cow. If he sold the cow at $2500, Jett made a profit of $2500 - $1900 = $600.. The answer is: 600.

Dr. Banks had 330 toothbrushes to give away to his patients. He gave away 53 toothbrushes in January. He gave away 67 toothbrushes in February. In March he gave away 46 toothbrushes. In April and May, he gave away the remaining toothbrushes, half each month. How many more toothbrushes did Dr. Banks give out in the busiest month versus the slowest month? Give the rationale and then the answer.
Let's think step by step. Through March, Dr. Banks gave out 53 + 67 + 46 = 166 toothbrushes. Before giving away toothbrushes in April, he had 330 - 166 = 164 toothbrushes remaining. Between April and May, he gave out the remaining 164 / 2 = 82 toothbrushes each month. Dr. Banks gave 82 toothbrushes in his busiest month and 46 toothbrushes during the slowest month. The difference would be 82 - 46 = 36 more toothbrushes in the busiest month.. The answer is: 36.

Cindy was hired to teach 4 math courses which required her to be in the classroom for 48 hours a week altogether. How much did Cindy earn for teaching 1 math course in a month with exactly 4 weeks if her hourly rate per class is $25? Give the rationale and then the answer.
Let's think step by step. In a week, Cindy spends an average of 48 hours / week / 4 courses = 12 hours / week for 1 math course. In a month, 1 math course is 12 hours / week x 4 weeks / month = 48 hours. Therefore, she earns $25 / hour x 48 hours / week = $1200 a month for 1 math course.. The answer is: 1200.