Answer:
3/5, 3/6, 5/6.....
Explanation:
The first step to execute as finding the three rational numbers, let's first understand what a rational number is;
• What is a rational number?
A rational number is a number that can be expressed as a fraction whose numerator (top number) and denominator (bottom number) are both integers, and it's denominator is not equal to zero

That means both 3/4 and 5/7 are all rational numbers
• Choosing rational numbers
So, any fraction lying between 3/4 and 5/7 is a rational number.
