Ruchi measured the area of her kitchen as 2. 81 times 10 Superscript 4 square units. When she recorded the area, she wrote 2. 81 times 10 Superscript 4 square feet. Which statement about her labeling of the units is true? She is correct because dimensions of rooms must always be measured in feet and area would be square feet. She is correct because 2. 81 times 10 Superscript 4 ftSquared is equivalent to 2, 810 ftSquared, which is an average size for a kitchen since area is always so much more than length. She is incorrect because 2. 81 times 10 Superscript 4 is around 30,000 so the units must be smaller than feet. She most likely measured in inches. She is incorrect because 2. 81 is a small number. She probably measured in yards to arrive at such a small value.

The rate of decay of a radioactive substance depends upon the amount present initially. the mass y (mg) of the radioactive substance cobalt-60 present in a sample at time t (years) is represented by the exponential equation y=50e −0.1315 t . answer the following questions in complete sentences. 1. how does the exponential equation above compare to the equation for simple interest that is compounded continuously? explain the similarities. 2. what is the initial amount of cobalt-60 in the sample? 2. how much cobalt-60 is left after 8.4 years? show your work. 3. what would be the y-intercept of the graph? what does it represent? 4. after how many years will the amount of cobalt-60 left be 6.25 mg? explain what happens to the cobalt-60 after 50 years? 5. discuss some “real-world” examples and uses of cobalt-60

The train station clock runs too fast and gains 5 minutes every 10 days. how many minutes and seconds will it have gained at the end of 9 days?

The volume of gas a balloon can hold varies directly as the cube of its radius. imagine a balloon with a radius of 3 inches can hold 81 cubic inches of gas. how many cubic inches of gas must be released to reduce the radius down to 2 inches?