Answer:
John answered 50 questions.
Step-by-step explanation:
Although five of John's answers were incorrect, 90% of his answers were correct.
This means that 5 is 100 - 90% = 10% of the total number of questions, n. So
John answered 50 questions.
Answer:
S = 128πx² + 64πx + 8π
Step-by-step explanation:
Suraface area of a cylinder is given by:
S = 2πrh + 2πr²
We know that the height is 3 times as big as the radius, hence:
h = 3r
so we can plug in the new h value and rewrite the S equation as:
S = 2πrh + 2πr²
S = 2πr(3r) + 2πr²
S = 6πr² + 2πr²
S = 8πr²
We're given in the question that the radius is (4x + 1) inches, so plug that into r.
Given: r = 4x + 1
Therefore,
S = 8πr²
S = 8π(4x + 1)²
S = 8π(16x²+8x+1)
S = 128πx² + 64πx + 8π
Answer:
12 cm
Step-by-step explanation:
The formula for the area of a trapezoid is written as:
1/2(b1 + b2)h
h = height = 16 cm
b1 = Length of one parallel side = 9cm
b2 = Length of second parallel side = ?
Area of trapezoid = 168cm²
The formula to find the length of the second parallel side =
b2 = 2A/h - b1
b2 = 2 × 168/16 - 9
b2 = 336/16 - 9
b2 = 21 - 9
b2 = 12cm
Therefore, the length of the second parallel side is 12 cm
To calculate the present value we shall proceed as follows:
from the present value table, the percentage corresponding to discount factor of 0.7008 in 5 years is 7%
therefore using the formula:
FV=PV(1+r/100)^n
where:
FV=$1000
PV=?
r=7%
hence:
1000=PV(1+7/100)^5
PV=1000/(1+7/100)^5
PV=712.986
