side note: multiplying by the LCD of both sides is just to get rid of the denominators
Answer:
For the code we have 3 selections.
The first selection is a digit that must be odd, so the options are {1, 3, 5, 7 ,9}
So we have 5 options.
The second selection is a letter from the set of all the letters (27) minus the set of the vowels (5)
So here we have 27 - 5 = 22 options
The third selection is also a letter from the previous set, but because each letter can be used only one time, and in the previous selection we already selected one of the letters, in this selection we have a letter less than in the previous selection.
Here we have 22 - 1 = 21 options.
The total number of combinations (of possible codes) is equal to the product of the number of options for each selection:
C = 5*22*21 = 2310.
There are 2310 different possible codes
You need to order the data, so
11, 12, 13, 14, 14, 15, 17, 17, 18, 18, 18, 20
Then find the middle of the data. Because there are 12 data points, the median will lie between the two 6th placed numbers
The two numbers are 15 and 17, so work out the mean of them. (15+17)/2 = 16
So the answer is B. 16
