48. If a floor is 20' wide, and 1 4/5 times as long, what is its area?

49. If 60 per cent of a job costs $10, what will the whole job cost?

50. If 70 per cent of a job is material, what is the cost of a job, the labor of which costs $22?

51. If a piece of work costs 7 per cent less than the contractor's estimate, which was $1900, how much was his additional profit?

52. A generally requires 10 1/2 hours to do a piece of work which B can do in 9 hours. With A's work as a basis, what should be the per cent of difference in their pay?

53. A shingle roof contains 88 squares, and must be done in two days; how many men laying 2 squares per day each will have to be hired?

54. What per cent of the cost of a job is the labor, if the material costs 61 per cent, and 10 per cent is allowed for profit?

55. In a heavy building, of mill construction, the bays are 8' to centers, timbers 12" X 14" X 20' long, and pieces of 6" X 8" are built into the walls to receive the ends of the flooring. The floor is to be 38' X 80', 4 1/2" thick, with floor openings aggregating 245 sq. ft. in area. Estimate the quantity of lumber necessary to construct the above floor, making no allowance for waste.

Note. - In the form of construction known as mill construction, the posts are placed from 7' to 9' apart, and support the floor timbers, which in turn support the heavy floor. The distances between the posts are called bays.

56. Make a stock list of the treads, risers, balusters, rails, and posts of a given flight of stairs.

57. Measure, make a stock list, and estimate the cost of the material of a given door.

58. A lumber dealer sells 100 ft. or 6 per cent of a lumber pile to one customer, 8 per cent to another, and the balance to a third at $22 per M. What does he receive from the last customer?

59. A and B start upon two jobs just alike. A receives 10 per hour and B, 80 per cent as much as A; if A does his work in 9 hours, how long ought B to spend upon his?

60. If A and B do their work in the same time, what per cent of A's pay should be withheld to make the cost of the two jobs the same?

61. If 12 men can build 180 ft. of fence in two days, how long will it take 18 men to build 500 ft.?

62. If a pile of lumber is worth $168 at 4 per ft., and if a part worth $23.52 is lost by fire, what per cent of the whole is left?

63. If it cost $5 per square to lay a floor complete, how much will it cost to lay a floor 49' long, 30' wide at one end and 9/15 as wide at the other?

64. A room is 24' X 36', of which 13 per cent is to be occupied by a closet; what will be the remaining area?

65. If 26 per cent of the labor, the total cost of which was $40, is furnished by A, and the rest by five others, what should each receive?

66. At $6.50 per M, how much will the brick in a given chimney cost?

67. A workman estimates his time at 25 per hour and bids $250 upon a contract. He receives the contract, which he fulfills in 883 hours. What per cent of his estimate has he made or lost by the transaction?

68. If a job costs $6, of which $2.25 is for material, what is the per cent of the cost of the material to the cost of the whole?

69. What are the total contents of two planks, if one contains 19 sq. ft., and the other 86 per cent of it?

70. If 60 ft. of lumber are cut for a certain piece of work, and but 42 ft. are used, what is the per cent of waste?

71. A and B could each accomplish about the same amount of work, but A was paid 30 and B 25 per hour. They were sent to do a piece of work together, which required 20 hours of each,man. A cuts the material which he uses with practically no waste, while B, through carelessness, wastes 21 1/4 sq. ft. costing $60 per M. Which is the less expensive man and by how much?

72. 1000 ft. of lumber weighing 3000 lb. was in the dryhouse 3 days, at the end of which time it had decreased 8 oz. per foot. What per cent of the original weight of the lumber had evaporated?

73. At the end of one week the lumber had thoroughly dried and its weight had decreased 40 per cent. What was its final weight?

74. If 1 cu. ft. of water weighs 62.42 lb., what would be the capacity of a tank to hold the water evaporated from the above lumber?

75. If a man pays $5 for tools, and earns $13.50 by his labor*, what per cent has he made upon the money invested?

76. A building is 65 ft. span in the clear. The lower chord of the truss is 10' X 14'. Allowing the chord to rest 15 in. upon each side, how many sq. ft. are there in the timber?

77. Measure and estimate the cost of the floor joists which support a given floor.

78. Counting four courses to the foot, how many bricks will it take to build a three-flue chimney 42' high, flues to be one brick each way?

79. A cistern has 60 bricks to a course and four courses to a foot. What is the height to the arch if 2880 bricks are used?

80. If it takes 21 bricks to lay a cubic foot, how many bricks are there in a wall 60' X 9' X 16" thick?

81. A young man spends $200 for his course in a trade school, and earns 75 per cent of it working for the school. How much does he have to obtain elsewhere?

82. After graduation the above young man earns $50 per month for one year as a carpenter, and saves 50 per cent of it. What per cent of his entire earnings for the three years was left after his school debt had been paid out of his savings?

83. If the area of a certain wall is 88 sq. ft., and 33 1/3 per cent of it is glass, what is the area of the glass?