Answer:
<em>y=0.10(t)+0.25 </em>
<em>27 minutes and 30 seconds </em>
Step-by-step explanation:
We know that you start with 25 cents as a service fee, this is for making the call. For each minute you talk, 10 cents are added. Multiply the number of minutes spent by 10 cents a minute for the cost based on the call. Then add the 25 cents service fee.
If you talked for 5 minutes:
y=0.10(5)+0.25
y=0.50+0.25
y=0.75
75 Cents
For three dollars, you would plug in 3 for y
3.00=0.10(t)+0.25
-0.25 -0.25
2.75=0.10(t)
divide both sides by 0.10 to get
27.5=t
You can talk for 27 minutes and 30 seconds
27 minutes
<u>Hope this helps :-)</u>
Answer:
5.91 kilograms
591,000 centigrams
Step-by-step explanation:
These two are WRONG:
59,100 kilograms
59.1 centigrams
The tip of the hand travels the circumference of a circle with radius (r) 9.5 cm every hour;
The formula for circumference of a circle (c) is:
c = πd = 2πr
So, for a circle with radius 9.5, the circumference is:
c = 2π(9.5)
= 19π cm
The tip travels 19π cm every hour, so in a day of 24 hours it will travel:
24 * 19π = 456π cm
(= 1432.566... ⇒ 1432.6 cm)
Step-by-step explanation:
x2 + 10x + 24
x2 + 6x + 4x + 24
x(x + 6) + 4(x + 6)
(x + 6) (x + 4)
The formula you can use for the withdrawals is that of an annuity. You have interest adding to the balance at the same time withdrawals are reducing the balance.
The formula I remember for annuities is
.. A = Pi/(1 -(1 +i)^-n) . . . . . i is the interest for each of the n intervals; A is the withdrawal, P is the initial balance.
This formula works when the withdrawal is at the end of the interval. To find the principal amount required at the time of the first withdrawal, we will compute for 3 withdrawals and then add the 7500 amount of the first withdrawal.
.. 7500 = P*.036/(1 -1.036^-3)
.. 7500 = P*0.357616
.. 7500/0.0347616 = P = 20,972.20
so the college fund balance in 4 years needs to be
.. 20,972.20 +7,500 = 28,472.20
Since the last payment P into the college fund earns interest, its value at the time of the first withdrawal is P*1.036. Each deposit before that earns a year's interest, so the balance in the fund after 4 deposits is
.. B = P*1.036*(1.036^4 -1)/(1.036 -1)
We want this balance to be the above amount, so the deposit (P) is
.. 28,472.20*0.036/(1.036*(1.036^4 -1)) = 6510.62
You must make 4 annual deposits of $6,510.62 starting now.
