3. Six one-acre plots of ground produced the following amounts of oats in five consecutive years:

Find the average number of bushels per acre for the six plots the first year; for each of the other years.

Find the average annual yield of the first plot for the five years; also for each of the other plots.

4. A herd of 18 cows has the following milk record in

5. Mr. Hopkins raised 1744 bushels of corn on 42 acres. What was the average yield per acre?

6. It is estimated that more than five billion tons of freight are moved over the public roads of the United States each year. It is also estimated that the average distance each ton is hauled is about ten miles and that it costs about 23¢ to haul one ton one mile. What is the total cost of hauling this freight? It is estimated that the cost of hauling one ton of freight one mile could be reduced to 8¢ if we had good roads. How much would be saved by good roads each year? This amount saved would build how many miles of good roads at $10,000 a mile?

Exercise 6. School garden problems

1. Each of the 40 pupils in the seventh grade of a certain school planted a garden 30 ft. long and 10 ft. wide according to the plat given in

Parsnips

2

3

Chard

4

Lettuce

5

Radishes

Peas.

1 Rows numbered 1 to 14 Figure 1. inclusive were one foot apart. The remaining rows were 2 ft. apart. They estimated the yield of each garden to 6 be as given below. (A bunch contains doz. vegetables.)

AMOUNT

7

8

Onions

9

10

Carrots

12

Head Lettuce..

14

Find the estimated value of the total yield of one garden.

2. The pupils harvested and sold all the produce from their gardens. The best ten gardens produced as follows: $23.40, $21.06, $19.75, $18.65, $18.10, $17.40, $17.15, $16.55, $15.40, $15.10. Four pupils failed to care for their gardens and they produced nothing. The poorest ten producing gardens produced as follows: $1.15, $2.35, $4.45, $6.10, $6.60, $7.25, $8.40, $9.65, $11.10, $13.40. Find the average value of the produce of the best ten gardens; of the poorest ten producing gardens; of the poorest ten gardens.

30 ft.

3. Find the average value of the produce of the 20 gardens whose returns are given above.

4. If the family of the pupil growing the best garden consumed $70.20 worth of vegetables in a year, what part of this expenditure for vegetables did the pupil produce in his garden?

5. In a certain city of 20,000 people there are 720 pupils in the seventh and eighth grades. If each pupil raises a garden as good as the best mentioned in problem 2, what is the value of the total produce of these gardens? If each pupil's garden is as good as the average of the 20 gardens whose values are given, what is the total value of their produce?

6. Assuming the yields to be the same as the estimates in problem 1, what would have been the value of the crop from one of these gardens if planted entirely in onions? In tomatoes?

7. Would it have been more profitable to plant the whole garden in peas or in beans? How much?

CHAPTER II

THE FORMULA. REVIEW OF FRACTIONS

9. Some useful terms. numbers is called their sum. addends.

The result of adding two or more

The numbers added are called

When one number, the subtrahend, is subtracted from another number, the minuend, the result is called their difference or remainder.

When two or more numbers are multiplied the result is called their product. The numbers multiplied together are called the factors of the product.

When one number is divided by another the result is called their quotient. The number divided is the dividend. The number by which it is divided is the divisor.

Exercise 7

1. The sum of two numbers is 15 and one of the numbers is 6. What is the other number?

2. Two addends together make 87. One of them is 29. What is the other?

3. The sum of three numbers is 37. Two of the numbers are 12 and 14. What is the third?

4. If the sum of two numbers and one of the numbers are known, how can the other be found?

5. If you know the sum of three numbers and two of the numbers, how can you find the other?

6. The difference of two numbers is 5 and the smaller number is 13. Find the larger number.

7. The difference of two numbers is 7. One of the numbers is 19. The other may be either of two numbers. Find both of them.

8. If you know the difference of two numbers and the smaller one, how can you find the larger one?

9. If you know the larger of two numbers and their difference, how can you find the smaller one?

10. The product of two numbers is 63, and one of the numbers is 7. Find the other factor.

11. The product of two factors is 714 and one of the factors is 17. What is the other factor?

12. The product of three factors is 5304 and two of them are 13 and 17. Find the third factor.

13. When a product and one of its two factors are known, how can the other factor be found?

14. When a product of three factors and two of the factors are known, how can the third factor be found?

42.

15. The quotient of two numbers is 6.

Find the divisor.

The dividend is

16. The quotient of two numbers is 18. The divisor is 35. Find the dividend.

17. When told the quotient of two numbers and the divisor, how can the dividend be found?

18. When told the quotient of two numbers and the dividend, how can the divisor be found?

10. Problems without numbers. In the "Directions for solving problems" you were told to think the process by which the things asked for may be found. This is often difficult but it can be done even if there are no numbers in the problem with which to compute the answer.

Tell what process you would use to find how much a boy would earn in a week if you knew how much he earns a day.