## 21 Apr A pure and an applied mathematician

A pure and an applied mathematician are asked to calculate 2 * 2. The applied mathematician's solution: We have, 2 * 2 = 2 *1/ (1-1/2). The second factor on the right hand side has a geometric series expansion 1/(1-1/2) = 1 + 1/2 +1/4 + 1/8 + ...