Fred brown and his sister, nancy, each have $15 in the bank. every week nancy plans to add $3 to her account. fred who loves to spend money when he has it, plans to add $1 to his account each week. how many weeks will it take nancy’s account to have twice as much money as fred’s account? (explain your thinking)

it will take 15 weeks for Nancy’s account to have TWICE as much money as Fred’s account

Step-by-step explanation:

Fred brown and his sister, Nancy, each have $15 in the bank

Initially both Fred and Nancy have $15

Every week Nancy plans to add $3 to her account

Let 'n' be the number of weeks she plans to add in her account

for 1 week, $3

For n weeks , its 3n

So amount of money in Nancy's account after 'n' weeks = 15 + 3n

Fret plans to add $1 to his account each week

for 1 week, $1

For n weeks , its 1n

So amount of money in Fred's account after 'n' weeks = 15 + 1n

Now we need to find out 'n' when

Nancy's account = 2 times of Fred's account

15 + 3n = 2(15+1n)

Distribute 2 inside the parenthesis

15 + 3n = 30 + 2n

Subtract 2n on both sides

15 + n = 30

Subtract 15 on both sides

n = 15

Hence, it will take 15 weeks for Nancy’s account to have TWICE as much money as Fred’s account

if you use photomath right away it will give you the answer not like this app that you have to wait for people.

answer: ratio of volume of cone (with 3 times the height and equal diameter) to volume of cylinder is 2 to 1. the value of π is not used.

step-by-step explanation:

radius is diameter/2 = 4.

area of circle is π r^2.

volume of cylinder is height × area of base = hπr^2 = 3(4^2) π = 48π cubic inches.

not knowing the formula for volume of cone, i calculate it using calculus (which is for calculating things).

volume of cone is integral 0 to h area(y) dy. area(y) is π r(y)^2. r(y) runs r to zero as y runs zero to h, r(0) = r, r(h) = 0.

r(y) = r - r/h y

area(y) = π (r - r/h y)^2 = π (r^2 - 2r^2y/h + r^2y^2/h^2) = π r^2(1-2y/h+y^2/h^2)

antiderivative area(y) = π r^2 (y-y^2/h+y^3/(3h^2))

integral 0 to h = π r^2(h-h^2/h+h^3/(3h^2) - (0)) = π r^2(h - h + h/3) = π r^2(h/3) = π/3 r^2 h

volume of this cone is π/3(4^2)18 cubic inches.

= 6 16 π = 96π cubic inches.

cone has twice the volume, 96/48.

cone height is 6 times the cylinder.

ratio of volume formula: π r^2 cancels.

cone over cylinder ratio is 6h/3 to h, 2 to 1.