Answer:
The value of x is 4.
The value of y is 26.
Explanation:
Here in qn a)
It has been given that n(AUBUC)=74
So we just add all components of n(AUBUC) and add it in an equation which equals to 74;
13 + 12 - x + x + 20 - x + 15 - x + 8 + 14 = 74
82 - 2x = 74
82 - 74 = 2x
8 = 2x
4 = x
So x is 4.
Now for qn b)
It has already been given that n(AUBUC) = 74 and n(U) = 100
so to find y we simply substract n(AUBUC) from n(U)
y = n(U) - n(AUBUC)
= 100 - 74
=26
Just ask me in the comments if you have any questions.