Can you please help me with these questions?

Question

They are based on the following information.

An Internet service provider offers three different plans for residential users. Plan A charges users $500 for the first year of service, and $80 per month thereafter. Plan B charges users $68 per month. Plan C is a "high speed" plan that offers 200% higher speeds for $92 per month.

1st question:

Isabelle has been using Plan A for over a year. She recently reviewed her plan and realized that if she had been using Plan B for the same amount of time, she would have saved $104 for Internet service over the entire period. At the time of her review, how many months had Isabelle been on Plan A?

2nd question:

Isabelle is now considering switching to either Plan B or Plan C for her home business, but she calculates that having the "high speed" plan will save her only approximately 45 minutes of work each month. At what minimum hourly rate, in dollars per hour, would she have to value her work (that is, how much more would she have to value one hour of free time over one hour of work time) for Plan C to be worth the extra cost over Plan B?

Answer 1

A = 800 + 80m

B = 68m

C = 92m

A - B = 104

Saving only 45 minutes in a month, makes the difference between the two negligible.

Are you sure it is only 45 minutes?

Answer 2

Plan "a" = $500/yr#1+$80mo.

" b = $816/yr.

" c = $1104/yr

The yearly charges are above.

(500+80x)-68(12+x)=104

" " -816-68x =104

12x-316 =104

" =420

x=35 months