In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Problem: a lady builds 7 cm length , 18 cm width , and 3 cm height box using 9 cubic cm cubes . what is the minimum number of cubes required to build the box ? 
Options: ['a ) 42', 'b ) 45', 'c ) 47', 'd ) 49', 'e ) 56']
a

Problem: a rectangular field is to be fenced on three sides leaving a side of 20 feet uncovered . if the area of the field is 800 sq . ft , how many feet of fencing will be required ? 
Options: a ) 100 feet , b ) 120 feet , c ) 150 feet , d ) 180 feet , e ) 186 feet
a

Problem: rain is falling at a rate of 10 centimeters per hour all over north carolina . somewhere downtown in north carolina a group of people are waiting for the rain to stop . if the rain filled a round puddle the with a base area of 300 square centimeters and a depth of 30 centimeters , how long did the people wait for the rain to stop ? 
Options: ['a ) 4 hours', 'b ) 11 hours', 'c ) 7 hours 15 minutes', 'd ) 3 hours', 'e ) 14 hours']

d