I'd like some advice please.

I have been training for a century ride on 6/7.

Heres what I have left and how I have it scheduled:

5-16 (Friday) I plan to ride 70 solo.
5-23 (Friday) I plan to ride 50 with a group. Do another 20 solo??
5-30 (Friday) ????
6-7 (Satruday) Century ride.

On the 23rd, should I ride 50 with the group and throw in another 20 solo? How many miles should I ride on 5-30 if I ride 50 the week before? How many if I ride 70?

I am putting in a run or two between bike rides and sometimes a short ride here and there.

Thanks for your advice.