5. If a locomotive move 5⁄8 of a mile in 11⁄12 of an hour, what is its speed per hour?
6. A man invested 1⁄5 of his money in land, .125 of it in stocks, $12,000 in a vessel, and had $55,500 remaining. How much did he invest in land?
7. Bought a square mile of land at $75 an acre. I reserved 160 acres of it for streets and alleys, and divided the remainder into lots each 66 feet front by 200 feet deep, all of which I sold for $15 per front foot. The expense of surveying, etc., was $2000. What did I gain?
8. How many balls, each 1⁄4 of an inch in diameter, are equal in weight to a ball of the same material 1 foot in diameter?
9. Find cost of material for making box, inside measurement 4 by 2 by 3 feet, of inch lumber, worth $30 per M., 1⁄25 of the lumber purchased being wasted. Include in the cost 7 dozen screws at $1.80 per gross.
THE STUDENTS WITH THEIR BOOKS.
10. What is the height of a rectangular cistern capable of containing 600 gallons, the bottom of which is 7 by 11 feet, inside measurement?