If you bet $1 on number 13 at roulette (or on any other number) then you win $35 if that number comes up, an event of probability 1/38, and you lose your dollar otherwise. Suppose you play 70 times. Use the Poisson approximation estimate the probability that

(a) You have won 0 times and lost $70, 

(b) You have won 1 time and lost $34.

(c) If you win 2 times you have won $2. Combine the results of (a) and (b) to conclude that the probability you will have won more money than you have lost is larger than 1/2.