Nick starts with 20 milligrams of a radioactive substance. the amount of the substance decreases by 14 each week for a number of weeks, w. he writes the expression 20(14)w to find the amount of radioactive substance remaining after w weeks. autumn starts with 5 milligrams of a radioactive substance. the amount of the substance decreases by 50% each week for a number of weeks, w. she writes the expression (1? 0.5)w to find the amount of radioactive substance remaining after w weeks. use the drop-down menus to explain what each part of nick's and autumn's expressions mean.

nick's

1/2: decay factor for each week

w: number of weeks

20: initial amount

(1/2)w: decay factor after w weeks

Autimn's

w:number of weeks

0.5: percent discount

1-0.5: decay factor for each week

Step-by-step explanation:

answer: the answer is (b) amie should have multiplied

step-by-step explanation: given a sphere and a cylinder with same radius and height.

let, 'r' be the radius of the cylinder and sphere and 'h' be the height of the cylinder. according to the question,

r = h.

now, the volume of the sphere will be

and the volume of the cylinder will be

therefore, we have

thus, ammie should have multiplied the volume of the sphere