We are given chance of winning a game is 1/50.
In decimal form 1/50 could be written as 0.02.
So, for each game, the chance of winning is 0.02.
Therefore, chance of loss would be = 1 -(0.02) = 0.98.
Chance of loss of 50 independent games = 0.98*0.98*0.98*0.98...... upto 50 times, that is (0.98)^50.
The chance of winning at least once = 1 - (0.98)^50.
We got (0.98)^50 = 0.36417
Therefore, 1 - (0.98)^50 = 1 - 0.36417.
We get 0.63583.
Therefore, correct option is c. 0.6358.