<span>Solution can be gained by using "Product of means = Product of extremes" concept. So the information we have is 23 miles on 1 gal and 135 mile on 'x' gal.
23 : 1 :: 135 : x
As per Product of means = Product of extremes,
23 multiplied x = 135 multiplied by 1.
And x will be 135 divided by 23 which is 5.86 gal
Now, we have to convert gal to liters, 1 gal = 3.78 liters,
so 5.86 gal = 5.86 multiplied by 3.78, which is 22.15 liters.
Hence, 22.15 liters of gasoline are needed for a 135 mile trip</span>
For the first month it will be $40 for the service and $35 to activate the phone service. After the first month it will only be $40 but for the first month it will be $75