Using the I=PRT formula, you can plug in some things we already know.
We know the principal, which is 43,200, we know the interest rate per year, and we finally know how much time he is going to have his money in there. But, he wants 4 months, and 4 months is 1/3 of the whole year, so we are going to use that to plug it in our formula. Now, we have
This equals to 2016.
But this is not our final answer. 2016 is just the amount of money he earned in those 4 months, not his whole savings, so we add 2016 to 43200 to get 45216
Do you have Photomath? You can scan the question and it will give you the answer!
Answer:
a 2.68
b 2.01
Step-by-step explanation:
1.34/2 =( 0.67 (F) )
(F)*4 = A
(F)*3 = B
It is the 1st equation at the top.
Reason: First check the equations to check that the initial amount is 497 kg. You can do this by setting x = 0 into all of the equations. The 3rd and 4th equations evaluate to 2 when x = 0 and so you can eliminate the bottom 2 equations immediately. Equation # 2 does not work since the half-life value of 1.040 kg is way to small (significantly smaller than half of 497 kg).
You can check that equation # 1 is the right one, by setting x = 0 and getting
y = 497*(1/2)^[(1/38) * 0] = 497
so the initial amount is 497
Also check that there is 1/2 the amount at time 38 (since the half-life is 38 days)
y = 497 * (1/2)^[(1/38) * 38] = 248.5
248.5 kg is half of 497 and so this checks out for equation # 1.
Since we know equation # 1 is good, now we evaluate at x = 4 to get
y = 497 * (1/2)^[(1/38) * 4] = 462.029
so our answer to the thousandth places is 462.029 kg.
<span>79.99/6.75%=5.399325 if you want the exact but 5.40 if you want rounded</span>