Here are the monthly charges for Jo's mobile phone Monthly charge 616
150 free minutes, then 18p per minute
150 free texte, then 18p per text
During one month, Jo makes 170 minutes of calls and sends 182 texte,
Work out the total charge for the month

Jo's Mobile Plan:
Fixed monthly charge = £16
Monthly 150 free minutes, post that 13p (or £0.13) per minute,
Monthly 150 free texts, post that 15p (or £0.15) per text
Jo's mobile phone usage details:
170 minutes of calls
182 texts
Total Charges for Jo = Fixed Monthly Charge + Charges for Calls + Charges for Texts
⇒ Total Charges for Jo = 16 + (170-150) × 0.13 + (182-150) × 0.15
⇒ Total Charges for Jo = 16 + (20) × 0.13 + (32) × 0.15
⇒ Total Charges for Jo = 16 + 2.6 + 4.8
⇒ Total Charges for Jo = 23.4
Hence, Jo should be charged £23.4 for the month.

Hope this helps !

Ithink the answer is d.