Answer:
3.6
Step-by-step explanation:
Number of weekend minutes used: x
Number of weekday minutes used: y
This month Nick was billed for 643 minutes:
(1) x+y=643
The charge for these minutes was $35.44
Telephone company charges $0.04 per minute for weekend calls (x)
and $0.08 per minute for calls made on weekdays (y)
(2) 0.04x+0.08y=35.44
We have a system of 2 equations and 2 unkowns:
(1) x+y=643
(2) 0.04x+0.08y=35.44
Using the method of substitution
Isolating x from the first equation:
(1) x+y-y=643-y
(3) x=643-y
Replacing x by 643-y in the second equation
(2) 0.04x+0.08y=35.44
0.04(643-y)+0.08y=35.44
25.72-0.04y+0.08y=35.44
0.04y+25.72=35.44
Solving for y:
0.04y+25.72-25.72=35.44-25.72
0.04y=9.72
Dividing both sides of the equation by 0.04:
0.04y/0.04=9.72/0.04
y=243
Replacing y by 243 in the equation (3)
(3) x=643-y
x=643-243
x=400
Answers:
The number of weekends minutes used was 400
The number of weekdays minutes used was 243
Given that Amistad deposited $2,163.27 in a savings account that earns 3.9% simple interest.
That means we need to use Simple interest formula to find the Amistad's account balance in nine months.
Simple interest formula is
A=P(1+RT)
Where P= principal amount = $2163.27
R= rate of interest = 3.9%= 0.039
T= time in years = 9 months = 9/12 years = 0.75
Now plug these values into above formula:
A=2163.27(1+0.039* 0.75)
A=2163.27(1+0.02925)
A=2163.27(1.02925)
A=2226.5456475
Hence Amistad's account balance in nine months will be approx $2226.55
47.098 rounded to the nearest tenth is 47.1
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