2/3+3/4=17/12=1.417 This is the anwser
There are three elements in that set.
B,D is the answer for your question
<u>Answer</u>

<u>Detailed Explanation </u>
To simply answer this, since .189 has three digits we are going to be inserting 999 as the denominator since it is a repeating decimal.

We could simplify the answer!

Therefore, the answer would simply be 

<u>Always Remember </u>
In the future, always remember whenever you have a three digit decimal and the problem asks you to convert it into a fraction, you should always insert 1000 as the denominator (the numerator is basically the decimal without the decimal point) and simplify if necessary.
The answer to 20+50 is 72