Task: Question Answering
Input (English): Problem: a gambler has won 40 % of his 40 poker games for the week so far. if, all of a sudden, his luck changes and he begins winning 70 % of the time, how many more games must he play to end up winning 60 % of all his games for the week ?
Options: a. 50, b. 60, c. 70, d. 80, e. 90
Output (English): d