Answer:91
Step-by-step explanation:
If the best grade is 100,91 is it.
 
        
                    
             
        
        
        
Sqrt 13 and 1.1919919991... are irrational, meaning that they can't be described in a fraction of one integer over another, like 1/3, 45/44 or 57/107, these numbers are rational. Most irrationals are known constants like e or π, endless non-repeating decimals, or roots of non-perfect numbers like 13, 7, 5 or 2.
        
             
        
        
        
He was 51 years old. He was 33 when he first started exploring. Then 17 years later he explored again so you add 17 +33 =50 . Then 11 years later he died so you add 11 to 50 =51
        
             
        
        
        
The rate of change is 15. We know this because 30 - 15 = 15, 45 - 30 = 15, and 60 - 45 = 15.
The next item in the sequence would be 75, since 60 + 15 = 75.