Insert the rational number between $7$ and $8$.

Hint: To find rational numbers between and two numbers, add the two numbers and divide it by $2$ and then to find another number add the outcome with the last number and do so on.

Complete step-by-step answer:
We have to find a rational number between $7$ and $8$. Rational numbers are the numbers which are written in the form $\dfrac{p}{q}$ where $(q \ne 0)$.
So to find a rational number we add the first term $7$ and second term $8$ and divide it by $2$.
Then we get, \[\dfrac{{7 + 8}}{2} = \dfrac{{15}}{2} \Rightarrow 1^{st}\] rational number.
\[2^{nd}\] rational number \[\dfrac{{\dfrac{{15}}{2} + 8}}{2} = \dfrac{{\dfrac{{15 + 16}}{2}}}{2} = \dfrac{{31}}{4}\].
\[3^{rd}\]rational number \[\dfrac{{\dfrac{{31}}{4} + 8}}{2} = \dfrac{{\dfrac{{31 + 32}}{4}}}{2} = \dfrac{{63}}{8}\].
And so on.

Note: You should have the basic concept of finding a rational number between two numbers after that you will get your answer.