A bag contains 5 red marbles and 10 yellow marbles. You randomly select two marbles from the bag. What is the probability that both marbles are red when you do not replace each marble before selecting the next marble? Write your answer as a decimal rounded to three decimal places.

answer: answer is b.

[m < b = 120º]

step-by-step explanation:

"standard form:

3x2 + 14x − 10 = 0

solutions based on quadratic formula:

x1   = −14 − √ 142 − 4×3×(−10) /   2×3   = −14 − 2 × √ 79 /   6   ≈ −5.296

x2   = −14 + √ 142 − 4×3×(−10) /   2×3   = −14 + 2 × √ 79 /   6   ≈ 0.629