Which of the following is a counterexample of, "all rational numbers are integers"? is not an integer. 3 is an integer. -1 is a rational number. π is a rational number.

It is (almost certainly) the first choice, however, you omitted the actual example there. See below.

Step-by-step explanation:

A counter-example to "All rational numbers are integers" is easy to find - it is any fraction that is reduced to simplest form and its denominator (bottom part) is not 1. Examples: 2/3, 7/5, 11/13 are all not integers but rational numbers and therefore are counter-examples to the statement. The statement is thus disproven. Please check your question - there is a value with the first choice that is likely one such fraction.

The remaining 3 choices to your answer are all not applicable.

1/2 is not an integer

Step-by-step explanation:

+25 = x

step-by-step explanation:

here x is the hypotenuse of a right triangle whose legs are 7 and 24.   by the pythagorean theorem, 7² + 24² must equal x²:

x² = 49 + 576 = 625.   thus, x = +√625 = +25 = x

- "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."