How long does it take for a simple with total number n to decay to 1/3n?

I'm not quite sure what this means can you explain it for me? The mean is always the best measure of center (describes the data the best).

Write an equation in standard form for the line that has slope - ⅓ and y-intercept 5.

Your pump empties the water from a swimming pool in 6 hours. When your friend's pump is used together with your pump, the pool is emptied in 1.5 hours. How long (in hours) does it take your friend's pump to empty the pool when working alone?

A city has two water towers. One tower holds 7.35 x 105 gallons of water and the other tower holds 9.78 x 105 gallons of water. What is the combined water capacity of the two towers? A) 1.713 x 106 B) 1.713 x 105 C) 1.713 x 104 D) 17.13 x 106

A triangle is equilateral if --___ sides are the same length. > at least 2 all 3 no only 2

The absolute value of negative eight minus twice a number

Which pair of expressions is equivalent? (A 4 (6x) and 10x B 4 (6x) and 24x C4x + 6x and 10x2 D 4x + 6x and 24x

How many minutes are in 2 years

A bakery has 4 trays with 16 muffins on each tray. The bakery has 3 trays of cupcakes on each tray. If 15 cupcakes are sold, how many muffins and cupcakes are left?

8 to 14 as a ratio as a fraction in simplest form.