2 yellow marbles, 7 red marbles, 1 green marble.....total of 10 marbles
probability of first picking a yellow marble : 2/10 reduces to 1/5
replacing the marble
probability of picking another yellow marble : 2/10 reduces to 1/5
probability of both is : 1/5 * 1/5 = 1/25 <==
Your answer is 5.
You can think of it as 7-2 because -2 is less than zero so you would have to subtract it from 7.
Answer : AB = 12
Explanation:
2x + 6 + 5x - 3 = 24
7x + 3 = 24
x = 3
AB = 2x + 6 = 2(3) + 6 = 12