Subject: mathqa
Question: in the faculty of reverse - engineering , 226 second year students study numeric methods , 423 second year students study automatic control of airborne vehicles and 134 second year students study them both . how many students are there in the faculty if the second year students are approximately 80 % of the total ?
Option: 
A: 666
B: 644 .
C: 618 .
D: 545
Answer: B