i. 2/7, 6/7
The three numbers lying between 2/7 and 6/7 are 3/7, 4/7, 5/7
ii. 4/5, 2/3
4/5 = 24/30, 2/3 = 20/30
The three numbers between 4/5 and 2/3 are 21/30, 22/30, 23/30
iii. -(2/3), 4/5
-2/3 = (-10)/15, 4/5 = 12/15
The three numbers between -2/3 and 4/5 are -9/15, -7/15, 4/15
iv. 7/9, -(5/9)
The three numbers between 7/9 and -5/9 are 6/9, 0, -4/9