Ineed asap! i just need on these 2 i don't understand!

tyrell wants to use the fermi process to estimate the number of blueberries that would fit in an empty city bus. as part of the process, he needs to estimate the volume of a typical city bus. he figures that a city bus is 40 ft long, 10 ft wide, and 10 ft tall

which estimate is the best approximates the volume of the bus ?
a) 4 × 10^1 ft^3
b) 4 × 10^2 ft^3
c) 4 × 10^3 ft^3
d) 4 × 10^4 ft^3

elisa wants to use the fermi process to estimate the number of ping pong balls that would fill a truck. as part of the process, she needs to estimate the volume of a ping pong ball. the diameter of a ping pong ball is about 40mm.

what estimate best approximates the volume of a ping pong ball ?

a) 3× 10^3 mm^3
b) 3× 10^4 mm^3
c) 3× 10^5 mm^3
d) 3× 10^6 mm^3

Gas mileage actually varies slightly with the driving speed of a car (as well as with highway vs. city driving). suppose your car averages 33 miles per gallon on the highway if your average speed is 54 miles per hour, and it averages 22 miles per gallon on the highway if your average speed is 75 miles per hour. answer parts (a) and (b) below. a. what is the driving time for a 2000-mile trip if you drive at an average speed of 54 miles per hour? what is the driving time at 75 miles per hour? the driving time at 54 miles per hour is nothing hours. (type an integer or decimal rounded to two decimal places as needed.) the driving time is at 75 miles per hour is nothing hours. (round to two decimal places as needed.) b. assume a gasoline price of $3.33 per gallon. what is the gasoline cost for a 2000-mile trip if you drive at an average speed of 54 miles per hour? what is the gasoline cost at 75 miles per hour? the gasoline cost at 54 miles per hour is $ nothing. (round to two decimal places as needed.) the gasoline cost at 75 miles per hour is $ nothing. (round to two decimal places as needed.)