Hmm difficult one but I think ima have to go with 2?????
The least common multiple would be 240.
120(2)=240 AND
80(3)=240
To get the congruent angles we shall use the sine rule since we have the length of at least 1 side and the values of the angles.
Base length=12 inches
Base angles=50°
Third angle=180-(100)=80°
thus applying the sine rule we shall have:
a/sin A=b/sin B=c/sin C
thus we can get the congruent side as follows:
a/sin 50= 12/sin 80
a=(12 sin 50)/sin 80
a=9.334 inches
since the sides are congruent then the other congruent side will have a length of 9.334 inches
Answer: A. 85.7
Step-by-step explanation:
Given : Two sections of a class took the same quiz.
Section A had 15 students who had a mean score of 80, and Section B had 20 students who had a mean score of 90.
We know that , 
Then , for section A :


Similarly in Section B, 
Total scores = Sum of scores in sec A+Sum of scores in sec B
=1200+1800=3000
Total students = Students in sec A +Students in sec B
=15+20=35
Now , the mean score for all of the students on the quiz =

Hence, the approximate mean score for all of the students on the quiz = 85.7
Thus , the correct answer is option A. 85.7.