Trying to keep the mileage but its hard

Trying to do about 20 miles a week.

I need to take it up to 25 next week.

Really tough. Just need more time in the week to allocate here. You cannot mess it up with drinks and stuff either.

how do I get to 35 miles?

20 miles
5, 5, 10

25 miles
6.5, 6.5, 12
6, 6, 13

30 miles
6, 6, 18
8, 8, 14

35 miles
6, 6, 20 (32)