Answer:
405
Step-by-step explanation:
So he built 5/9 of the wall, than added the extra 180 bricks to finish the wall.
so 5/9 + 180 = 9/9
so 180 = 4/9 Because 5/9 + 4/9 = 9/9
So to figure out how many bricks are in the wall we want to know what 1/9 of bricks equals and to work this out we need to divide 180 by 4
which equals 45.
Now we know that 1/9 = 45
so now to figure out what 9/9 is just multiply 45 by 9 which equals 405
Answer:
2.5 pi
Step-by-step explanation:
Comment
If you were trying to get the area of a whole circle, you would use
Area = pi r^2
You have to modify the formula to show that just part of the circle has an area that you are interested in.
The new formula is
Area = (theta/360) pi r^2
Givens
r = 30 cm
theta = 100
Solution
Area = (100 / 360) * pi * r^2 Substitute the givens into this formula
Area = (5 / 18) * pi * 3^2 Expand
Area = (5 / 18) * pi * 9 Cancel 9 into 18
Area = 5/2 * pi
Area = 2.5 * pi
Answer:
2520cm²
Step-by-step explanation:
Surface area = sum of the area of all the bases.
Area of bottom base = 28 * 30 = 840
Area of right base = 25 * 30 = 750
Area of left base = 17 * 30 = 510
Area of two triangles = ( 15 * 28 ) / 2 = 210 * 2 = 420
Then add all the areas together to find surface area
Surface area = 840 + 750 + 510 + 420 = 2520cm²
Relevant Formulas:
Area of a rectangle = length * width. This formula was used to find the area of the bottom base, the right base and the left base
Area of a triangle = ( height * base length ) / 2 . This formula was used to find the area of the sides which are triangles.
Answer:
there is an economic principle that states that 1 dollar today is worth more than 1 dollar in the future, since an invested dollar could earn interests and gain value.
For example, we can assume a 6% interest rate (0.5% monthly interest rate), and using the present value formula we can determine the present value of $100:
- given to us in 30 days = $100 / (1 + 0.5%)¹ = $99.50
- given to us in 150 days = $100 / (1 + 0.5%)⁵ = $97.54
- given to us in 300 days = $100 / (1 + 0.5%)¹⁰ = $95.13
In order to calculate the value of $100 given to us tomorrow, we would need to determine a daily interest rate = 6% / 360 = 0.00017
- $100 given to us tomorrow = $100 / (1 + 0.00017)¹ = $99.98
since the amount of money is not that large and the interest rate is rather low, the difference in value is not that large. But imagine if you used a 24% interest rate instead of 6% (monthly interest rate = 2%)
- $100 given to us in 30 days = $100 / (1 + 2%)¹ = $98.04
- $100 given to us in 150 days = $100 / (1 + 2%)⁵ = $90.57
- $100 given to us in 300 days = $100 / (1 + 2%)¹⁰ = $82.03
as the interest rate increases, the present value decreases.
