SPECIFIC GRAVITIES.-WATER 1. 107. A Table showing the weight of each substance compared with an equal volume of pure water. A cubic foot of rain-water weighs 1000 ounces, or 624 ib. Avoir. To find the weight of a CUBIC FOOT of any substance named in the table, remove the decimal point three places toward the right, which is multiplying by 1000, and the result will show the number of ounces in a cubic foot. 11.350 7.235 7.250 1.333 .804 2.386 1.063 3.700 .750 2.716 14.000 2.750 1.900 @ $12, and 7 @ $15. 9 doz., & @5/% @4/6. 3 doz. No. 4 @ 5 shillings per doz., and 6 doz. No. 5 @ 4 shillings sixpence per doz. 8 × 10, or 8 by 10 in. 8 inches wide and 10 inches long. MIXED PROBLEMS. 109. 1. The area of a map laid down on the scale of an inch to a mile is 4 sq. ft. 4 sq. in. What number of acres are represented? Ans. 371200A. 2. A merchant marks his goods with two prices, one for ready money, and the other for a credit of 6 mo. What ratio ought the two prices to bear to each other, allowing 6% per annum simple interest? Ans. 100 to 103. 3. A grocer buys two kinds of tea, one at $.80, and the other at $.50 a pound, and mixes them in the proportion of 5 parts of the cheaper to 7 parts of the dearer. At what price per pound must he sell the mixture, so as to realize 25% profit on the cost? Ans $.843. an acre has 4. A circular plot of ground containing a walk all around it on the inside, 2 yards wide. Find the area of the space within the walk. Ans. 68.849 P. 5. A butcher paid $152 for calves and sheep, paying $6 apiece for the calves, and $4 a head for the sheep; he sold of his calves and of his sheep for $46, and in so doing lost 8% on their cost. How many of each did he purchase? Ans. 12 calves; 20 sheep. 6. I borrowed a sum of money at 6% annual interest, and loaned it at 8% interest semi-annual, receiving compound interest for the second half-year, and gained thereby at the end of the year $860. What was the sum borrowed? Ans. $39814.81. 7. If a reservoir 24 ft. 8 in. long by 12 ft. 9 in. wide is full of water, how many cubic feet must be drawn off to lower the surface 9 in.? Ans. 2353 cu. ft. 8. The sales of a publisher amount to $250000. Onefourth of the sales are made at a profit of 33%, threefifths at a profit of 20%, and the remainder at a loss of 25%. Find the cost of the stock sold. Ans. $214438.88. 9. If a cannon-ball 8 inches in diameter weighs 128 lb., what will be the weight of a similar ball 15 inches in diameter? Ans. 843 lb. 10. Smith owed Jones $1800, due July 18; he paid $560 before, and the remainder after the whole was due. When were the payments made, if they were 45 days apart? Ans. June 17 and Aug. 1. 11. The triangular gable of a certain building has a base of 45 feet, and the perpendicular height is 16 ft. What will the lumber cost required to cover both gables, at $1.87 per hundred feet, board measure? Ans. $13.50. 12. The first of 6 boys can run 3 rods as soon as the second can run 2 rods; the second 5, as soon as the third 6; the third 7, as soon as the fourth 8; the fourth 9, as soon as the fifth 10; and the fifth 15, as soon as the sixth 14. How many rods will the sixth run while the first is running 135 rods? Ans. 128 rods. 13. A walk 12 feet wide surrounds a square garden. The area of the walk being an acre, what is the area of the inclosed square? Ans. 4 A. 76.6 P. 14. What sum must a man save annually, commencing at 21 years of age, to be worth $40000 when he is 50 years old, his savings being invested at 6% compound interest? Ans. $543.18. |