Dear student,
0.8 can be written as 8/10
0.9 can be written as 9/10
To obtain three rationals between 8/10 and 9/10 we will multiply both of them by 4/4.
8/10 × 4/4 = 32/40
9/10 × 4/4 = 36/40
Three rationals between 8/10 and 9/10 are -
33/40 , 34/40 , 35/40.
Hope you understood,
Your teacher.