Assertion: Three rational numbers between $\frac{2}{5}$ and $\frac{3}{5}$ are $\frac{9}{20}, \frac{10}{20}$ and $\frac{11}{20}$.
Reason: A rational number between two rational numbers $p$ and $q$ is $\frac{1}{2}(p+q)$.
(a) Both Assertion and Reason are true and Reasom is a correct explanation of Assertion.
(b) Both Assertion and Reason and Reasom are true but Reasom is not a correct explanation of Assertion.
(c) Assertion is true and Reasom is false.
(d) Assertion is false and Reasom is true.
(a) Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
Rational number between $\frac{2}{5}$ and $\frac{3}{5}$ :
$\frac{\frac{2}{5}+\frac{3}{5}}{2}=\frac{1}{2}=\frac{10}{20}$
Rational number between $\frac{2}{5}$ and $\frac{10}{20}$ :
$\frac{\frac{2}{5}+\frac{10}{20}}{2}=\frac{18}{40}=\frac{9}{20}$
Rational number between $\frac{3}{5}$ and $\frac{10}{20}$ :
$\frac{\frac{3}{5}+\frac{10}{20}}{2}=\frac{22}{40}=\frac{11}{20}$
So, Assertion and Reason are correct (property of rational numbers). Also, Reason is the correct explanation of Assertion.