3x=x+40(vertically opposite angle)
thus ,
X= 20
The probability of obtaining a 1 is 1/13, so the probability of not getting a 1, that is, the probability of getting a ball different from 1, is 1- (1/13)=12/13, which is 0.923
If nine out of ten students prefer math class over lunch then that's 90%. Which means 10% of the 200 don't prefer it. 200/10= 20 people do not prefer math
