Answer: 0.05
======================================
Explanation:
There are 4 blue out of 8+4+4 = 16 marbles total
The probability of picking blue the first time is 4/16 = 1/4. Let A = 1/4.
After we pick a blue marble, we have 4-1 = 3 left over out of 16-1 = 15 left over. The values go down by 1 because of the "without replacement" key phrase. The probability of picking blue again is 3/15 = 1/5. Let B = 1/5
Multiply the two values for A and B
A*B = (1/4)*(1/5) = 1/20
Convert to decimal form (use a calculator)
1/20 = 0.05
Alternatively, you can convert 1/4 and 1/5 to decimals first
A = 1/4 = 0.25
B = 1/5 = 0.20
and then multiply
A*B = 0.25*0.20 = 0.05
Note: the answer 0.05 is equivalent to 5%. You would move the decimal point 2 spots to the right to convert to a percentage.
