On a game show, a secret 4-digit number is formed using the digits 1, 2, 3 and 4, with repetition permitted. The contestant's winnings for each number of correct matches of individual digits is shown....

Extracted text: On a game show, a secret 4-digit number is formed using the digits 1, 2, 3 and 4, with repetition permitted. The contestant's winnings for each number of correct matches of individual digits is shown. $1000 for one match $2000 for two matches $5000 for three matches $10 000 for four matches How much should the contestant wager of his previous winnings in order to double his money, on average?