Anyone able to help with these using a venn diagram approach:

Trying to learn probability and struggling with following two questions - any help appreciated:

1. A group of people took a literacy and numeracy test. 85% of applicants passed the literacy test and 75% of applicants passed the numeracy test. What are the maximum and minimum proportions of people who did not pass either test?

2. 100 students. 36 study French/42 study Spanish/47 Study German.
10 study both French and Spanish
12 Study both Spanish and German
9 study both French and German

What is the probability that a student chosen at random studies all three?

I tried using Venn diagrams as I was instructed to, but kept getting stuck