Which graph represents the piecewise function?

Ineed to find the answer to number 2

Savannah talked for 6 minutes on the phone. catherine talked for n minutes. catherine talked 3 times as long as savannah. how long did nathan talk?

For each phone call robert makes, he pays $0.10 for the first minute and $0.05 for each additional minute. what is the cost for two 5 minute calls ? a $0.60b $0.30c $0.15d $0.45 show work.