In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[EX Q]: Problem: if a and b are the roots of the equation x 2 - 9 x + 20 = 0 , find the value of a 2 + b 2 + ab ? 
Options: a ) 57 , b ) 59 , c ) 61 , d ) 63 , e ) 65
[EX A]: c

[EX Q]: Problem: each child has 5 crayons and 14 apples . if there are 10 children , how many crayons are there in total ? 
Options: a ) 22 , b ) 65 , c ) 12 , d ) 36 , e ) 50
[EX A]: e

[EX Q]: Problem: in expressing a length of 61.472 km as nearly as possible with the 3 significant digits , find the percentage error ? 
Options: a ) 0.35 % , b ) 0.4 % , c ) 0.045 % , d ) 0.6 % , e ) none of these
[EX A]:
c