A car's fuel tank holds 14 gallons. If gasoline costs $3.45 per gallon, how much does it cost to fill an empty tank?

The cost is the number of gallons times the price per gallon: $14\cdot3.45=48.30$ dollars, choice H. You can compute it in pieces: $10\cdot3.45=34.50$ and $4\cdot3.45=13.80$, and $34.50+13.80=48.30$. Choice F ($17.25) is $5\cdot3.45$. Choice G ($41.40) is $12\cdot3.45$. Choice J ($51.75) is $15\cdot3.45$. Each of these multiplies the price by the wrong number of gallons, so check that you use $14$, the capacity of the full tank. Estimating $14\cdot3.5=49$ confirms the size of the answer.