Here is a story: Lin bought 4 bags of apples. Each bag had the same number of apples. After eating 1 apple from each bag, she had 28 apples left.
1. Which diagram best represents the
A
28
story? Explain why the diagram
represents it.
X + 1 x + 1 x + 1] x + 1
B
28
2. What part of the story does x
represent?
х
Х
х
Х
C
X-1
X-1 X- 1 x - 1
28
3. Describe how you would find the
unknown amount in the story.

tube or goog would be a great resource to with that question

- "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."