Which set is closed under the operation multiplication?

a.
{1, 2, 4}

b.
{0.5, 1, 2}

c.
{0}

d.
{1, 2, 3, 4, 5}

Under normal conditions, 1.5 feet of snow will melt into 2 inches of water. during a winter season high in the mountains, 301 feet of snow fell. how many inches of water will there be when the snow melts?

Find the measure of the interior angles of the following regular polygons: a triangle, a quadrilateral, a pentagon, an octagon, a decagon, a 30-gon, a 50-gon, and a 100-gon.

Which value of m will create a system of parallel lines with no solution? y = mx - 6 8x - 4y = 12