Εικόνες σελίδας
PDF
Ηλεκτρ. έκδοση

on June 18 for $462.90; June 21, deposited $240; June 25,

[blocks in formation]

21. Bought of A 974 bushels of oats at 19 cents; 1,328 bushels of corn at 28 cents; 1,726 bushels of wheat at 58 cents. Sold him 30 acres of land at $39 an acre. Which was indebted to the other? How much?

22. Two railway trains start at the same time from the opposite ends of a division 212 miles long. One runs at an average rate of 29 miles an hour, and the other at 24 miles. How far apart will they be at the end of 3 hours? 4 hours? 5 hours? 6 hours?

23. A stock train has 29 cars. Each car contains 19 cattle, whose average weight is 1,450 pounds.

$5.25 a hundred.

What do they bring?

24. Change to a 5-place decimal.

They sell for

25. Add 5 mi. 180 rd. 4 yd. 2 ft.; 16 mi. 79 rd. 3 yd. 1 ft.; 26 mi. 136 rd. 2 yd. 2 ft. 8 in.; 29 mi. 278 rd. 5 ft. 10 in.; 46 mi. 316 rd. 1 yd. 1 ft. 10 in.

26. Multiply 2 lb. 10 oz. 16 pwt. 15 gr. by 36.

[ocr errors]

27. Reduce 10 square yards to a fraction of an acre. 28. If 18 gallons of water be mixed with 22 gallons of grape-juice, the water is what per cent of the mixture?

29. How many barrels (31 gallons) will a cylindrical cistern hold, its diameter being 8 feet and its depth 10 feet?

30. A delivery pipe 3 inches in diameter has what percentage of the capacity of a pipe whose diameter is 33 inches?

31. A man whose watch shows Chicago time finds that it is 27 min. 36 sec. slower than local time. What is his longitude?

32. How many wagon-loads of sand, each containing 83% of a cubic yard, will fill your school-room?

33. If a pile of wood 6 feet high and 4 feet wide extend across the front of your school lot, what is it worth at $4.75 a cord?

34. What is the altitude of a triangle whose area is an acre, and whose base is 10 feet?

35. A square tract of land containing 6,969.6 acres costs $80 an acre. The number of silver dollars required to pay for it will exactly cover its boundary: what is the distance around the field? What is the length of one side?

NOTE. What is the diameter of a silver dollar? What is the distance around the field in feet? What, then, is the length of one side? Prove the problem.

36. Divide 160 square rods into 18 equal parts.

37. What is the cost of plank 2 inches thick to build a walk 250 feet long and 6 feet wide at $21.50 a thousand feet?

38. A's money is 25% less than B's C's. If A has $324, how much has B?

and 25% more than How much has C?

39. What will discharge a debt of $586.80 at a discount of 20% and 5% ?

NOTE. The second discount is computed on the remainder of the first. 40. Change 3 inches to the decimal of a rod.

41. To what single discount is a discount of 331% and 5% equal?

42. 1049760 is the product of three factors, two of which are 216 and 15. What is the third?

43. What is the difference between 3% of $1,800 and 333% of the same?

44. A school-room is 15′ × 60′ × 72′. The ventilator is 2' x 2'. What must be the velocity of the air in feet per second to change the air in 8 minutes?

45. The above school-room is lighted from the long sides. If the window space is 10% of the floor space, how many 4' x 9' windows are there on each side?

46. The value of a house is 87% of the value of the lot. Both cost $9,645. What is the value of each?

47. Put the following in the form of a bill, supplying names: 36 collars at 163; 6 shirts at $1.50; 12 pairs cuffs at 25; 15 handkerchiefs at 30%; 8 pairs hose at 45; 8 ties at 35; 3 suits underwear at $2.50; 1 hat at $2.50; 2 pairs gloves at $1.25.

48. The width of the blackboard on one side of your school-room is what per cent of its length?

49. If a gallon measure, cylindrical in form, is 4 inches in diameter, what is its height?

50. What is the weight of a solid block of gold 14 feet thick that will exactly cover the top of your teacher's table? (19.4.)

51. A discount of 20% and 24% having been allowed me, my bill is $386.40. What was the original bill?

52. What is the weight of a dozen silver spoons, each weighing 3 oz. 5 pwt. 7 gr.?

[ocr errors][merged small][merged small][ocr errors][merged small]

54. Write the answer to the following question: What common fractions can be changed to pure decimals?

55. Give a rule for changing a common fraction to per cent; for division of a decimal by a decimal; for changing a decimal to a common fraction; for finding the per cent which one number is of another.

56. What is the interest on $560 for 3 years, 4 months, at 7% ?

57. What is the cost of an article which is sold for $225, after a deduction of 10% from the marked price, it having been marked so as to gain 331%?

58. An article cost $7.29. What should be its marked price to permit a discount of 10% and still gain 10%?

59. How many articles, each weighing 3 oz. 6 pwt. 20 gr., can be made from 9 lb. 8 oz. 19 pwt. 4 gr. of the same material?

60. Find the time from March 12, 1891, to Jan. 5, 1896.

SECTION VIII.

268. APPLICATIONS OF PERCENTAGE.

1. The methods of calculation taught in percentage are applied to the solution of practical problems. In all such problems the pupil must determine which of the three general problems is involved.

2. In each of the general problems three numbers are employed. They are called the Base, the Percentage, and the Rate Per Cent.

3. The Base, in a problem in percentage, is the number to which the other two numbers are referred. It is the answer to the question, "per cent of what?"

4. The Rate per Cent is the decimal fraction expressed in hundredths which shows the part which the percentage is of the base.

5. The Percentage is the number whose relation to the base is expressed by the rate per cent.

6. In each of the general problems two of these three numbers are given to find the third.

7. In the first general problem the base and rate per cent are given to find the percentage; in the second, the base and percentage to find the rate per cent; in the third, the percentage and rate per cent to find the base.

NOTE. A fourth number, called the Amount, is employed in some of the Applications of Percentage.

269. PROFIT AND LOSS.

1. The Cost of an article is the expenditure involved in its purchase or production, and is usually expressed in money.

« ΠροηγούμενηΣυνέχεια »