Answer:

Step-by-step explanation:
The probability can be defined as the ratio between the possible events and the total number of outcomes.
In this case, according to the image attached, the total number of outcomes is 11, because they are 11 marbles in total.
Now, the specific event is all shaded marbles or labeled with a multiple of 3. With this specific characteristics 6 marbles, because there are 5 shaded marbles and 6 is a multiple of 3. So, the possible events are 6.
Therefore, the probability is

The right answer is the last choice.
Answer:
7
Step-by-step explanation:
median is the number at the center of the rest
3,1,8], 7 [,6,5,1
<u>Answer-</u>
<em>The correct answer is</em>
<em>∠BDC and ∠AED are right angles</em>
<u>Solution-</u>
In the ΔCEA and ΔCDB,

As this common to both of the triangle.
If ∠BDC and ∠AED are right angles, then 
Now as
∠BCD = ∠ACE and ∠BDC = ∠AED,
∠DBC and ∠EAC will be same. (as sum of 3 angles in a triangle is 180°)
Then, ΔCEA ≈ ΔCDB
Therefore, additional information can be used to prove ΔCEA ≈ ΔCDB is ∠BDC and ∠AED are right angles.