Question

A gas company has the following rate schedule for natural gas usage in single-family residences:

Monthly service charge $8.80

Per therm service charge
1st 25 therms $0.6686/therm
Over 25 therms $0.85870/therm


Construct a function that gives the monthly charge C for x therms of gas.

Answer 1

0.85.................................................................................

Answer 2

So if X is greater than 25, you would need to subtract 25 from X and then multiply it by the rate. After that, add 25.515. So your function should look something like this:

X > 25, 0.85870 * (X - 25) + 25.515

So that's assuming the first 25 are priced at the 0.6686 rate. So the ones after 25 are then priced at the 0.85870 rate.