So for $5, let's calculate each company's minutes for that much money.
Company X: First subtract the time for the first minute.
5 - 0.49 = 4.51
Then divide by 0.16, and you get about 28 minutes.
28 + the original 1 minute = 29 minutes
Company Y: $5 - 0.57 = 4.43
4.43 / 0.12 = about 36 + the original one minute = 37 minutes
So Company Y gives her more minutes for 5 dollars, and also 8 more.