The library has 6 new books it would like to display near the checkout desk. The librarian plans the six books between a set of bookends. How many different ways can the books be placed between the bookends if order is important?

The answer is 6 factorial or 6!

6! = 6 * 5 * 4 * 3 * 2 * 1

which equals 720

Step-by-step explanation:

- "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."