Amy has a box containing 6 white, 4 red, and 8 black marbles. she picks a marble randomly. it is red. the second time, she picks a white marble. in the third attempt, amy picks a white marble again. amy has not replaced the marbles she picked.
the probability that the fourth marble amy picks is black is . if amy picks a black marble in the fourth attempt, the probability that in the fifth attempt she will pick a red or a black marble is .

The probability that the fourth marble Amy picks is black

The probability that in the fifth attempt she will pick a red or a black marble P(R∩B) =

Step-by-step explanation:

To find  the probability that in the fifth attempt she will pick a red or a black marble P(R∩B) .

The total marble in beginning=6+4+8=18

After 3 attempts, the total  marbles left=18-3=15

The number of black marbles =8

The probability that the fourth marble Amy picks is black

As four marble has already picked up, then the total marbles left in the box

=18-4=14

Now, as a red marble is already picked in 1st attempt , the number of red marbles in the box now= 4-1=3

And a black marble is already picked in fourth attempt , the number of black marbles in the box now= 8-1=7

Now P(R∩B)=P(R)+P(B)=

complete the steps to find the area of the trapezoid.

area of rectangle = 256   square units

area of triangle 1 = 24  square units

area of triangle 2 = 16  square units

area of triangle 3 =   96 square units

area of trapezoid = 120  square units

step-by-step explanation:

answer: option a.

step-by-step explanation:

you know that the quadrilateral opqr ( a four sided figure) is inscribed in circle. this means that all its vertices are on the circle.

then, by definition, the opposite angles of the quadrilateral are supplementary, this means that the sum of their measures is 180 degrees.

you can observe in the figure that the angles ∠opq   and the angle ∠orq   are opposite, therefore:

then, can be used to d to calculate the measure of ∠opq