A bag contains four yellow marbles, six red marbles, five blue marbles, six white marbles, and four black marbles. What is the theoretical probability of pulling a white marble from the bag?

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.

3/4 = c/36 i need with this fraction proble.

Ineed with question three. i don't understand how i'm supposed to achieve 3 marks.