Ren sets aside $1,000 into an online savings account with an annual interest rate of 2.3%, compounded annually. How long will it take for the

money in his account to double?

It will take 30.48 for the money in his account to double.

Step-by-step explanation:

Interest compounded anually:

With an investment of P, the amount compounded annualy after t years that you will have is given by:

In which r is the interest rate, as a decimal.

Ren sets aside $1,000 into an online savings account with an annual interest rate of 2.3%

This means that . So

How long will it take for the money in his account to double?

This is t for which A(t) = 1000*2 = 2000. So

It will take 30.48 for the money in his account to double.

SI=(P*R*T)/100

P=2000

R=1.5

T=6

SI=(2000*1.5*6)/100

=(2000*9)/100

=180

Neil will earn interest of 180

The answer is in the image 

The answer is in the image 

The solution is in the following image

The wood before starting =12 feet

Left wood=6 feet

Wood used till now=12-6=6 feet

Picture frame built till now= 6/(3/4)

=8 pieces

Therefore, till now 8 pieces have been made.

The answer is in the image 

Let the father's age be x and son's be y

10 years before-

Father age=x-10

sons age=y-10

Given,

x-10=10(y-10)

x-10=10y-100

Given present age of father=40

therefore,

x=40

40-10=10y-100

10y-100=30

10y=130

y=130/10

y=13

Therefore present age of son=13years

Given height of gymnasium is 5/6 height of 30 foot ball

therefore height of gymnasium=5/6 * 30

=25 feet

The solution is given below