Answer: C. 10.
Step-by-step explanation:
Let x = Number of times you have to go to the gym in order for it to cost the same amount.
Given: Monthly pass fee = $90
Additional charge = $4
Total amount = (Monthly fee) + (Number of times) (Additional charge)
Total amount = 90+4x (i)
Payment for each time you go to the gym = $13
Total amount = 13x (ii)
From (i) and (ii) , we get
Hence, the number of times you have to go to the gym in order for it to cost the same amount= 10
Hence, the correct option is C. 10.