Answer:
20
Tips:
Its easy math if its trouble use a caclulator
Answer:
4.46cm
Step-by-step explanation:
Volume of a frustum is expressed as;
V = (1/3) * π * h * (r₁² + r₂² + (r₁* r₂))
h is the height of the frustum
r₁ and r₂ are the radii of its ends
V is the volume
Given
V = 9100cm₃
r₁ = 10cm
r₂ = 30cm
Substitute
9100 = (1/3) * (3.14) * h * (10² + 30² + (10* 30))
9100 = 1/2(3.14)*h*(100+900+300)
9100 = 1.57*h*(1300)
9100 = 2,041h
h = 9100/2,041
h = 4.46cm
Hence the height of the cap is 4.46cm
The element 
is the entry in the 1st row and 3rd column of the matrix, which, in this case, is 7.
Edit: Got my rows/columns mixed up! Row 1, Column 3 is actually -1, as the original poster pointed out.
Answer:
Step-by-step explanation:
Time varies inversely with speed if the distance is constant. This means that if speed increases, the time it will take to cover the same distance will reduce
t = k/s
Where t = time
k = constant of inverse proportionality
s = speed
It takes James 4 hours to get to his destination when he travels at 65 miles per hour
4 = k/65
k = 65×4 = 260
t = 260/s
If he drove 15 miles/ hour faster, the new speed is 65 + 15 = 80miles/hour.
The time it will take him is
t = 260/s
t = 260/80 = 3.25 hours
The amount of time he would save is
4 hours - 3.25 hours = 0.75 hours
Converting 0.75 hours to minutes, we multiply by 60
Amount if time saved in minutes = 0.75×60 = 45 minutes
