Help please

Tracy has a cell phone plan that provides 250 free minutes each month for a flat rate of $29. For any minutes over 250, Tracy is charged $0.35 per minute. Which of the following piecewise functions represents charges based on Tracy's cell phone plan?

A. f(x)={29,x less than or equal to 250} {20+.35x,x>250}
B. f(x)={29,x>250} {20+.35x,xless than or equal to 250}
C. f(x)={29,xless than or equal to 250} {.35x,x>250}
D. f(x)={29,xless than or eual to 250} {29+.35(x-250),x>250}

1 answer

Not A. It charges double for minutes over 250

Not B. flat rate up till x=250

Not C. Drops the $29 for x>250

Clearly D. Only charges the .35 for those minutes over 250.