What is with this ?!

Q1
1 = 1 = 2^1-1
1 + 2 = 3 = 2^2-1
1 + 2 +2^2 = 7 = 2^3-1

Assuming that the pattern continues indefinitely, find the sum of:
1 + 2 + 2^2 + 2^3+....+ 2^19 + 2^20.

Q2
A and B are two cyclits who intend to travel the same journey. A leaves at 12 noon and averages 20km/h and B leaves 45minutes later and average 25km/h. How far does B have to travel to catch up to A.