Answer:
a) <em>t</em> ≥ 5
b) (see below)
Step-by-step explanation:
First, make note of the info you are given and what you're trying to do:
- at midnight, 5°C
- drops consistently 2°C per hour
- finding <em>t</em>
- <em>t </em>= # of hours past midnight when temp. was past -4°C
- put <em>t</em> on a number line
So, first, you need to find the first point at when the temperature goes past -4°C. Notice that the question is asking for past -4°C, not -4°C<em> and</em> past. This means we're not including -4°C.
Every hour, we're dropping by 2°C. You can draw a visual to better understand the situation. See the image below.
So we know that starting from 5 am, we are lower than -4°C.
This is 5 hours from midnight.
So <em>t</em> ≥ 5. This means that the number of hours past midnight when the temperature was colder than -4°C was 5 or more hours.
On the number line, draw a circle on 5 (between 4 and 6), but shade it in because it includes 5. Then, shade or highlight to the right of that circle to the end of the number line.
This shows that <em>t</em> is equal to or greater than 5.
<span>P(at least 1 ) = 1 - P(exactly none) = 1 - (4/5)^6 = .738
Hope this helps!!!:)</span>
Answer:
∴ The the surface area of the wall is 
.
Step-by-step explanation:
Given that,
The length of rectangular wall is 
.
The width of rectangular wall is 
The length of doorway is 
The width of doorway is 
and, we have to find the surface area of rectangular wall.
Now,
The length of rectangular wall is .
The width of rectangular wall is
∴ Total surface area of a rectangular wall 
Total surface area of a rectangular wall is .
Again, The length of doorway is
The width of doorway is
∴Total surface area of doorway 
Total surface area of doorway is 
.
∴The remaining surface area of a rectangular wall is 
∴ The the surface area of the wall is .
Answer:
hghjghgjh
Step-by-step explanation:
Answer:
At 7% $54,000
At 9% $156,000
Step-by-step explanation:
Let x be the amount invested at 7%, Then 2x + 48000 will be the amount invested at 9%
We know that:
7% = 0.07 & 9% = 0.09
So we can write the interest equation as follows:
0.07x + 0.09 (2x + 48000) = 17820
0.07x + 0.18x + 4320 = 17820
0.25x + 4320 = 17820
Subtracting 4320 from both sides of the equation we get:
0.25x = 17820 - 4320
0.25x = 13500
Dividing both sides of the equation by 0.25 we get:
x = 13500 / 0.25
x = $54,000 invested at 7%
&
2 x 54000 + 48000
= $156,000 invested at 9%
Hence the amount invested at 7% is $54,000.
& the amount invested at 9% is $156,000.
