2/3 of 18...." of " means multiply
2/3 * 18 = 36/3 = 12....she has memorized 12 words so far
The product of c and 2 is greater than or equal to 20
c*2 >=20
divide by 2
c>=10
Answer:

Step-by-step explanation:
Probability refers to chance of happening of some event.
Conditional probability is the probability of an event A, given that another event B has already occurred.
denote the two boxes.
In box
:
No. of black balls = 1
No. of white balls = 1
In box
:
No. of black balls = 2
No. of white balls = 1
Let B, W denote black and white marble.
So, probability that either of the boxes
is chosen is 
Probability that a black ball is chosen from box
= 
Probability that a black ball is chosen from box 
To find:probability that the marble is black
Solution:
Probability that the marble is black = 
Answer:
¯\_(ツ)_/¯
Step-by-step explanation:
¯\_( ͠° ͟ʖ °͠ )_/¯