Answer:
Step-by-step explanation:
a) The amount of concern is ...
(total interest)/(number of payments) = interest/payment
$14,644.95/120 ≈ $122.04 . . . . amount of interest per payment
__
b) The ratio of concern is ...
(total interest)/(total payments) × 100% = 14,644.95/39,644.95 × 100%
≈ 36.94% . . . . percent of total payments that is interest
Answer:
∠ BAC = 80°
Step-by-step explanation:
The sum of the interior angles of quadrilateral ACDB = 360°
DB and DC are tangents to the circle, thus
∠ DBA = ∠ ACD = 90° ( angle between tangent/ circle at point of contact )
Thus
∠ BAC + 90° + 90° + 100° = 360°
∠ BAC + 280° = 360° ( subtract 280° from both sides )
∠ BAC = 80°
Given Information:
Area of rectangle = 16 square feet
Required Information:
Least amount of material = ?
Answer:
x = 4 ft and y = 4 ft
Step-by-step explanation:
We know that a rectangle has area = xy and perimeter = 2x + 2y
We want to use least amount of material to design the sandbox which means we want to minimize the perimeter which can be done by taking the derivative of perimeter and then setting it equal to 0.
So we have
xy = 16
y = 16/x
p = 2x + 2y
put the value of y into the equation of perimeter
p = 2x + 2(16/x)
p = 2x + 32/x
Take derivative with respect to x
d/dt (2x + 32/x)
2 - 32/x²
set the derivative equal to zero to minimize the perimeter
2 - 32/x² = 0
32/x² = 2
x² = 32/2
x² = 16
x = 
ft
put the value of x into equation xy = 16
(4)y = 16
y = 16/4
y = 4 ft
So the dimensions are x = 4 ft and y = 4 ft in order to use least amount of material.
Verification:
xy = 16
4*4 = 16
16 = 16 (satisfied)
There are 6! = 720 ways of arranging the lamps.
If the leftmost lamp is red, there are 3 choices of lamp in the leftmost position, and the remaining 5 can be placed in any order, so there are 3×5! = 360 ways of arranging the lamps and the leftmost is red.
Hence there is a 360/720 = 1/2 probability that the leftmost lamp is red.
Ignoring lamp color for the moment, the probability of arranging 3 lit lamps and 3 unlit lamps is the same, 1/2.
Since Ryan arranges the lamps randomly by color, then turns 3 of them on randomly, the two events are independent. So
P(leftmost red AND leftmost lit) = P(red) × P(lit) = 1/2² = 1/4
