Surface area of cylinder

The answer is C. .

Step-by-step explanation:

To solve for the surface area of this cylinder, start by using the cylinder surface area formula, which is . Next, plug in the information given from the problem into the formula, which will look like . Then, simplify the equation, which will look like . The next step is to simplify the equation further, which will look like . The final answer is .

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."

the answer is 15 to your question