Question

Which shows a rational number plotted correctly on a number line?

Answer 1

The second illustration is correct. Note that the given number, -21/2, is between -24/2 and -20/2. Identifying and using the LCD (here, 2) makes the comparison and placement much easier than they would be otherwise.

Answer 2

Answer with explanation:

We know that any negative number is always represented to the left of zero on the  number line.

In first graph:

The number -3.5 is represented to the right of zero.

It is represented in between 2 and 4.

But we know that -3.5 lie between -4 and -2.

Hence, option: 1 is incorrect.

In second graph:

 The number -21/2 is  a negative number and lie between -11 and -10

              Hence, option: 2 is correct.

In third graph:

The number -7/2 lie between -4 and -3.

But in the graph it is plotted to the left of -4 whereas it should be to the right of -4.

Hence, option: 3 is incorrect.

In fourth graph:

The number 9/2 is equal to 4.5

and it must lie between 4 and 5.

i.e. it should be plotted to the right of 4.

Hence, option: 4 is incorrect.