Please help and show work . need fast ... college algebra The half-life for thorium-227 is 18.72 days. The amount A (in grams) of thorium-227 after t days for a 10-gram sample is given by A(t)=10⋅0.5^t/18.72 How long will it take before 1 grams of thorium-227 is left in the sample? Round your answer to the hundredths place. days

62.17 days

Step-by-step explanation:

The computation of the number of days  is shown below:

Given that

A(t)=10 × 0.5^(t ÷ 18.72)

1 = 10 × 0.5 ^ (t ÷ 18.72)

0.1 = 0.5 ^ (t ÷ 18.72)

Now consider the log in both sides

ln(0.1) = ln(0.5)^ (t ÷ 18.72)

ln(0.1)  ÷  ln(0.5) = (t ÷ 18.72)

3.321928095  = (t ÷ 18.72)

So, t = 62.17 days

With the help of log, we can easily compute it

$3720

step-by-step explanation:

taxable income = $31000

as per the 2018-2019 us tax bracket, the tax rate is 12% for an individual whose taxable income is between $9,526 to $38,700.

so, the tax to be paid by him = 12% of 31000

= 0.12 * 31000     [12% converted to decimal as 0.12]

= $3720