I think it is 0.14 or 0.24
I hope this helps :) I didn't show my work on one I want you to learn how to do this. On a test I won't be there. :) Here you go.
Answer:
For example 
Step-by-step explanation:
A non-unit fraction is a fraction of which the numerator is not equal to one. Additionally, the question does not state to pick three different ones and thus you can pick any fraction that when multiplied by three (since you take three fractions together) add up to a whole number (I'm picking the whole number to be one here just to make it simple), where the numerator is not equal to one of course.
For example:
, because 3·
=
= 1
Infinitely many solutions can be found: for example 
Answer:
0.2601
Step-by-step explanation:
There are 19C16 = 969 ways for Lester to choose 16 of the 19 objects.
There are 12C11 = 12 ways to choose 11 vases, and 7C5 = 21 ways to choose a non-vase, for a total of (12)(21) = 252 ways to choose exactly 11 vases in 16 objects.
So, the probability of interest is ...
252/969 ≈ 0.2601
_____
nCk = n!/(k!(n-k)!) ... the number of ways to choose k objects from n