The numbers 3 and 4 can be written as 13 and 14.
Since we want to find six rational numbers between the given numbers, multiplying the numerator and denominator of the above numbers by 6 + 1 i.e. by 7, we get 721 and 728, which are equivalent to the given numbers.
As 21<22<23<24<25<26<27<28,721<722<723<724<725<726<727<728
Therefore, six rational numbers between 3 and 4 are:
722,723,724,725,726,727