An electric heater uses 9 kWh per day at a cost of 0.4 AED per kWh. How much does it cost to run the electric heater for 5 days?

i had this question and the answer was 3.15 miles.

martina travels from school to her mom's office. from there, she walks to school. after school, she walks to the library and then to a friends house before finally ending back at home. find martina's total distance traveled.

a) 0 miles  

b) 0.4 miles  

c) 1 mile  

d) 3.15 miles