There are two decks of cards each deck containing 20 cards, with numbers from 1 to 20 written on them. A card is drawn at random from each deck, getting the numbers x and y What is the probability that log x + log y is a positive integer. (Logs are taken to the base 10.)
A. 3/200
B. 7/400
C. 29/100
D. 5/400
Answer:B
There are two decks of cards each deck containing 20 cards, with numbers from 1 to 20 written on them. A card is drawn at random from each deck, getting the numbers x and y What is the probability that log x + log y is a positive integer. (Logs are taken to the base 10.)
A. 3/200 B. 7/400 C. 29/100 D. 5/400