 #### Prompt 1:

2016:

It is  5:30 AM, and as a helicopter pilot you’ve just been told there’s an injured man on a boat you need to get to a hospital. The boat is going towards where you are at 10 mph, but is currently 400 miles away. You need to get him as soon as possible, but you only have 6600 lbs of fuel in your helicopter, which burns 1200 lbs per hour, and always travels at 150 mph. Also, you need to account for 30 min of fuel spent hovering over the boat to get the man into the helicopter, and 1 extra hour of fuel due to helicopter standards. When do you leave and why?

#### Prompt 2:

2017:

You are a researcher in the Falkland Islands You’ve been asked to estimate the penguin population. The current population is 1000 penguins. 500 pairs produce one chick per pair per year. At the end of each year there is a loss of 20% of the total population. Figure out how many penguins there will be at the end of seven years. Develop a formula that solves the problem.

#### Prompt 3:

2018:

When designing a stairway, an architect can use the riser-tread formula 2h +d = 25, where h is the riser height, in inches, and d is the tread depth, in inches. For any given stairway, the riser heights are the same and the tread depths are the same for all steps in that stairway.

The number of steps in a stairway is the number of its risers. For example, there are 5 steps in the stairway in the figure above. The total rise of a stairway is the sum of the riser heights as shown in the figure.

An architect wants to use the riser-tread formula to design a stairway with a total rise of 9 feet, a riser height between 7 and 8 inches, and an odd number of steps. With the architect’s constraints, which of the following must be the tread depth, in inches, of the stairway?