If a is the percentage of pages with text only, b is the percentage containing text and diagrams, and c is the percentage with diagrams only then:
a+b+c=98%, a+b=88%, b+c=32%.
Therefore 88%+c=98%, c=10%; b+10%=32%, b=22%; a+22%=88%, a=66%.
A) either text or diagram: a+c=66%+10%=76%.
B) diagrams only: c=10%.
C) text only: a=66%.