Answer:k=0.67
Step-by-step explanation:
Answer:
254 cm² (to 3 s.f.)
Step-by-step explanation:
Area of shaded region
= area of large circle -area of smaller circle

Radius of large circle= 15cm
Radius of smaller circle= 12cm
Area of shaded region
= π(15²) -π(12²)
= 225π -144π
= 81π
= 81(3.14)
= 254.34
= 254 cm² (3 s.f.)
The volume of a sphere is defined as:
V=(4*pi*r^3)/3
then, if we double the radius of the sphere (r=2r):
V=(4*pi*(2r)^3)/3
V=(4*pi*(2^3*r^3))/3
V=(4*pi*r^3)/3*8
Then, the answer is that if you double the radius of the sphere, its volume is increased 8 times.
Answer:
A.
Step-by-step explanation:
< means open circles
x-21<3 x≥21
-x+21<3 x<21
18<x<21 and 21≤x24
so the union of will be 18<x<24