45 is the answer
hope this helps :)
<span>Let us assume that the rate of decay follows a 1st
order reaction. Therefore the formula for rate of decay is:</span>
<span>A = Ao e^-kt --->
1</span>
Where,
A = final value after time t
Ao = initial value at t zero
k = rate constant
t = time elapsed
First let use find for the value of constant k. We know
that the formula for half-life is:
t-half life = ln 2 / k
Finding for k:
5730 = ln 2 / k
k = 1.21 * 10^-4 yr^-1
Since it is stated that A = 0.00061 Ao, therefore
substituting all the values into equation 1:
0.00061 Ao / Ao = e^(-1.21 * 10^-4 yr^-1 * t)
Finding for t:
t = 61,173.98 years
<span>The person died about 61,174 years ago.</span>
I believe it might’ve made 2,400 books, because if you divide 70 from 1680 you get 24, meaning it’s pressing about 24 books per hour, if it’s printing twice that you would multiply 48 by 50 and get 2,400.
Okay. So 3/5 in decimal form is 0.6. 7/10 in decimal form is 0.7. When you put them in order from least to greatest, the order would be 0.15, 3/5, 7/10, 0.85. Converting fractions to decimals and looking at the different places and what not could help make solving questions like these much easier.
MAB is 120, so m∠ADB is half of mAB=60
AC is the diameter, which means arc ABC is 180, and m∠ADC=90
m∠BDC=m∠ADC-m∠ADB=90-60=30
so the angle BDC is 30 degree