⇒Fill 15 to the intersection of X,Y,Z (X∩Y∩Z), I use green color to fill the blank on this part.
⇒Determine the number in the intersection of X and Y after excluding (X∩Y∩Z). Do the same for the intersection of X and Z, and for the intersection of Y and Z.
Intersection X and Y
(X∩Y) - (X∩Y∩Z) = 25 - 15 = 10
Intersection X and Z
(X∩Z) - (X∩Y∩Z) = 22 - 15 = 7
Intersection Y and Z
(Y∩Z) - (X∩Y∩Z) = 22 - 15 = 7
Fill the blank, I use blue color
⇒ Determine X, Y, and Z after excluding all the intersection
X = |X| - |X∩Y| - |X∩Z| - |X∩Y∩Z|
X = 42 - 10 - 7 - 15
X = 10
Y = |Y| - |X∩Y| - |Y∩Z| - |X∩Y∩Z|
Y = 39 - 10 - 7 - 15
Y = 7
Z = |Z| - |X∩Z|- |Y∩Z| - |X∩Y∩Z|
Z = 40 - 7 - 7 - 15
Z = 11
I fill with purple color
⇒ Last, fill outside the venn diagram
72 - all numbers on the venn diagram
= 72 - 10 - 10 - 7 - 15 - 7 - 7 - 11
= 5
I fill with pink color
Refer to image attached