12. The cylinder to the left contains two congruent hollow cones. If the
cylinder's height is 20 inches and its diameter is 14 inches, find the
volume of the solid.

The  volume of the solid is

Step-by-step explanation:

step 1

Find the volume of the cylinder

The volume of the cylinder is given by the formula

we have

---> the radius is half the diameter

substitute the values

step 2

Find the volume of the two congruent hollow cones

The volume of the two cones is given by the formula

we have

---> is the same that the radius of cylinder

----> is half that the height of cylinder

substitute

step 3

To find out the volume of the solid subtract the volume of the two cones from the volume of the cylinder

x + y = 90 5x – 10y = 90 90 – 10y = 5x 90 + 10y = 5x

step-by-step explanation:

last month maria hiked the 5-mile mountain trail a number of times and she hiked the 10-mile canal trail several times. let x represent the number of times she hiked the 5-mile trail, and let y represent the number of times she hiked the 10-mile trail. if she hiked a total of 90 miles, which equation can be used to find the number of times maria hiked each trail? x + y = 90 5x – 10y = 90 90 – 10y = 5x 90 + 10y = 5x

circumference divided by 3.141592654 then timesthe radius twice

step-by-step explanation:

circumference divided by 3.141592654 then timesthe radius twice