Since we know a triangle only has 180 degrees we can say:
99+3x+x+5=180
Then we can solve for x:
4x+104=180
4x=76
x=19
The answer is D hope this helps
20
20 = 1 x 20
100 = 5 x 20
I'm not sure what exactly you did wrong, but I agree with you that the sample size is too small, so the correct answer will probably be the fourth options. Hope that this gives you some confidence, and 'm sorry not to be able to help you any further...
