An electric car is capable of going 225 km on a single charge. with a full charge to start, how many additional charges will it need to travel from seattle, washington, to san diego, california, a distance of 1257 mi?

We are given that the capacity of 1 charge is 225 km, so the rate of consumption is:

rate = 1 charge / 225 km

The total distance that must be travelled is:

distance = 1257 mi = 2022.945 km

So the total charges needed is:

total charges = 1 charge / 225 km * 2022.945 km

total charges = 9 charges

Since we started with 1 full charge, so additional charges needed is only 8.

Answer:

8