How long will take for a $3000 savings account to double its value at simple interest rate of 10%?

just plug the numbers into the formula you know:

A = P(1+rt)
If all you want is the multiplication factro, then
A/P = (1+rt)
so,
2 = (1+.06t)

How long will it take $4,000 to grow to $16,000 if invested at 5% compounded monthly?

To determine how long it will take for a savings account to double its value at a given interest rate, we can use the formula for simple interest:

A = P(1 + rt)

where:
A = final amount
P = principal amount (initial deposit)
r = interest rate per period
t = number of periods (time)

In this case, we want the savings account to double its value, so the final amount A would be $3000 x 2 = $6000.

Now let's plug in the given values into the formula and solve for t:

$6000 = $3000(1 + 0.10t)

Dividing both sides of the equation by $3000:

2 = 1 + 0.10t

Subtracting 1 from both sides:

1 = 0.10t

To solve for t, we divide both sides by 0.10:

t = 1 / 0.10
t = 10

Therefore, it would take 10 time periods for a $3000 savings account to double its value at a simple interest rate of 10%. The time periods could be years, months, or any unit specified by the context or the terms of the savings account.