A bag contains 6 blue coins and 7 red coins. A coin is removed at random and replaced by three of the other color. Part 1 out of 3
What is the probability that the removed coin is blue? Enter your answer as a simplified fraction.

The probability that the removed coin is blue is ———

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.