Three small squares are drawn inside a larger square as shown. What is the length of the line marked with a question mark?

19

Step-by-step explanation:

let the smallest square be A, medium square is B and the largest is C ;

as the length side of the main square is 28, we can find that,

A= 28-22 = 6

C= 28-15 = 13

So to find B,

A+B+C = 28

B = 28-A-C

B = 28-6-13 = 9

So the line with questioned mark is,

28-9 = 19

the volume is the product of the area of the base, 3x(3x+4), and the height, 3x-1

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."