April 2021
Problem of the Month

Snowtime in Colorado

Last month, the city of Fort Collins, Colorado was hit with a snowstorm that dumped 20" of snow.   This snow yielded about 10" snow = 1" water (that is, 10 inches of snow melts down to 1 inch of water).
Mr. P's driveway is 20' x 22', and the sidewalk that he must shovel is 99' x 4' on one side and 76' x 4' in the front (Mr. P lives on the corner).

How many pounds did Mr. P have to lift to clear his driveway and sidewalk of the snow?

HINT: Use the following in your computations:
1 cubic inch = 0.004329 U.S. gallons
1 gallon of water weighs 8.33 pounds

Extra Credit:
I rounded up the numbers in the problem.   To get extra credit, use the actual totals:
Fort Collins officially received 19.6 inches of snow and 2.31 inches of precipitation (water) during the storm.

Solution to the Problem:

Mr. P had to shovel 11,839.4 pounds.

The area of Mr. P's driveway = 20' x 22' = 440 sq. ft. = 63,360 sq. inches
The area of Mr. P's front sidewalk = 76' x 4' = 304 sq. ft. = 43,776 sq. inches
The area of Mr. P's driveway = 99' x 4' = 396 sq. ft. = 57,024 sq. inches
The total square inches to be shoveled = 164,160 square inches.
The number of cubic inches to be shoveled = 164,160 x 20 = 3,283,200 cubic inches.
Divide by 10 (10" snow = 1" water) to get the number of cubic inches of water: 328,320 cubic inches of water.

Now multiply by .004329 to get the number of gallons of water: 1,421.29728 gallons.
Now multiply by 8.33 to get the number of pounds: 11,839.4 pounds which equals 5.9 tons.
And now you know why Mr. P has a sore back!
Disclaimer: A neighbor came over to help me shovel.
I split the shoveling up over three days.

The answer to the extra credit:
The total square inches to be shoveled = 164,160 square inches.
The number of cubic inches to be shoveled = 164,160 x 19.6 = 3,217,536 cubic inches of snow.
Multiply by .117857 (19.6" snow = 2.31" water) to get the number of cubic inches of water: 379,209 cubic inches of water.

Now multiply by .004329 to get the number of gallons of water: 1,641.598358 gallons.
Now multiply by 8.33 to get the number of pounds: 13,674.5 pounds which equals 6.8 tons.

Correctly solved by:

1. Veena Mg	Bangalore, Karnataka, India
2. Colin (Yowie) Bowey **	Beechworth, Victoria, Australia
3. Anna T. Vice	Landon School, Bethesda, Maryland

** solved the extra credit

Send any comments or questions to: David Pleacher