Answer:
380 minutes
Explanation:
Given: Plan A : Monthly fee $25
Additional per minute charges = 9 cents
Plan B = Monthly fee = $32.60
Additional per minute charges = 7 cents
The equation for cost usage under plan A will be,
X = 25 + 0.9 y
wherein y denotes the number of minutes consumed
Similarly, for Plan B, the equation would be,
X = 32.6 + 0.07 y
since total cost under the two has to be same at the same number of minutes.
Equating the two , we get,
25 + 0.09 y = 32.6 + 0.07y
⇒ 0.02y = 32.6 - 25
⇒ 0.02y = 7.6
⇒ y = [tex]\frac{7.6}{.02}[/tex]
⇒ y= 380
Hence till the usage level of 380 minutes, Plan A will not cost more than Plan B.