Answer:
35
Step-by-step explanation:
Given
n (A) = 15
n (B) = 20
Students who do not like any subject = 5
Hence, number of students who would like either both or either of the two subjects = 60-5 = 55
n (A or B) = n (A) + n (B) - n (A and B)
Number of students linking both the subjects
55 - 15-20
= 55-35 = 20
Number of students linking only one subject = 60-20-5 = 35
Plan A = 9 +0.17x
Plan B = 21 +0.12x
9+0.17x = 21+0.12x
X=240
9+0.17(240)=49.8
21+0.12 (240)=49.8
240 minutes and cost $49.80 each
I'm pretty sure it's the first one