3/4 can be written in decimal form as,
0.75 is a repeating decimal. So, 0.75 with repeating decimal can be written as 0.757575.
We have to find three rational numbers between 0.75 (3/4) and 0.757575.
So, three rational numbers between 0.75 (3/4) and 0.757575 should have values in between 0.75 (3/4) and 0.757575 itself.
So, three rational numbers between 3/4 and 0.75 are 0.753, 0.754 and 0.756.