in an intercollegiate competition that lasted for 3 days , 185 students took part on day 1 , 150 on day 2 and 200 on day 3 . if 100 took part on day 1 and day 2 and 110 took part on day 2 and day 3 and 50 took part on all three days , how many students took part only on day 3 ?
"day 1 & 2 = 100 ; only day 1 & 2 ( 100 - 50 ) = 50 , day 2 & 3 = 110 ; only day 2 & 3 ( 110 - 50 ) = 60 , only day 3 = 200 - ( 50 + 60 + 50 ) = 40 answer : e"
subtract(185, add(add(50, 100), divide(add(50, subtract(150, add(add(100, 110), 50))), 2)))