Given that,
y varies directly with x and y = 10 when x = 20.
To find,
The value of y when x = 15.
Solution,

Put x = 20 and y = 10

Put k = 1/2 and x = 15 to find the value of y.

So, the value of y is 7.5
Answer: Find answers in the attached documents
Step-by-step explanation:
Answer:
The height is 20 cm.
Step-by-step explanation:
First, we have to know that the volume formula is V = πr²h and the base area of cylinder is a circle. So we can let πr² be 77 cm² . Then we have to substitute the following values into the formula :



Let πr² be 77,
Let v be 1540,



