A sample of a radioactive isotope had an initial mass of 820 mg in the year 1995 and decays exponentially over time. A measurement in the year 2002 found that the sample's mass had decayed to 380 mg. What would be the expected mass of the sample in the year 2007, to the nearest whole number?

How many kilometers are equal to 5 miles? use 1 mile ≈ 1.61 kilometers. !

For every corresponding pair of cross sections, the area of the cross section of a sphere with radius r is equal to the area of the cross section of a cylinder with radius and height 2r minus the volume of two cones, each with a radius and height of r. a cross section of the sphere is and a cross section of the cylinder minus the cones, taken parallel to the base of cylinder, is the volume of the cylinder with radius r and height 2r is and the volume of each cone with radius r and height r is 1/3 pie r^3. so the volume of the cylinder minus the two cones is therefore, the volume of the cylinder is 4/3pie r^3 by cavalieri's principle. (fill in options are: r/2- r- 2r- an annulus- a circle -1/3pier^3- 2/3pier^3- 4/3pier^3- 5/3pier^3- 2pier^3- 4pier^3)

Th perimeter of a rectangular garden is 150 feet. the length is 50 feet longer than the width, w. which equation could be used to calculate the width of the garden? a.) 2w+ 2(w-50) =150 b.) 2w+50 + 2w =150 c.) 2(w+50) + w =150 d.) 2w+ 2(w + 50) = 150 need asap. will give brainliest !