3. If the speed of a train is 50 miles an hour, what is the time it takes in going one mile?

4. If the speed of an auto is 55 miles an hour, what is the time it takes in going two miles?

5. If the time for one mile is 36 seconds, what is the speed per hour?

Exercise

1. In Lieutenant Murray's record flight on June 25, 1919, from Atlantic City to New York, he covered a distance of 140 miles in 61 minutes. What was his time per mile?

2. When Lieutenant Sharpnack flew on July 2, 1919, from San Diego to San Francisco, a distance of 610 miles in 4 hours, 32 minutes, what was his rate in miles per hour?

3. On September 18, 1919, when Rohlfs in a Curtiss Wasp triplane rose 19,500 feet in 9 minutes, 42.4 seconds, what was his increase in elevation in feet per minute?

1. Read from the above table the number of plants to an acre if the plants are 9 inches apart.

2. How many to the acre if the plants are two and a half feet apart?

3. How many if four feet apart?

4. How many trees can be planted to the acre if they are set out 20 feet apart?

5. How many if planted 25 feet apart?

6. If lemon trees are planted 20 feet apart, how many will there be to the acre?

7. If orange trees are planted 22 feet apart, about how many will there be to the acre?

8. If walnut trees are planted 60 feet apart, about how many will there be to the acre?

1. Read from the above table the weight of a cubic foot of cast iron.

2. Find the weight of a cubic foot of lead.

3. What does a cubic foot of cast brass weigh?

4. What is the weight of a cubic foot of aluminum?

5. What does a cubic foot of glass weigh?

6. Find from the table the weight of a cubic inch of cast iron.

7. A cubic inch of aluminum weighs how much?

8. How much does cast brass weigh per cubic inch?

1. Find from the above table the number of board feet in a

board 1" x 8", 12 feet long.

2. How many board feet in a board 1" x 6", 18 feet long? 3. How many board feet in a board 1" × 18", 16 feet long?

4. How many board feet in a plank 2" × 12", 18 feet long? 5. How many board feet in a timber 12" × 12", 24 feet long?

Exercise

1. How much lumber in 10 pieces of 1" x 8", 12 feet long? 2. How much in 24 pieces of 4" x 4", 16 feet long? 3. How much in 50 pieces 8" x 8", 18 feet long?

4. How much in 40 pieces 4" x 8", 18 feet long?

5. How much in 52 pieces 4" x 4", 16 feet long, and 240 pieces 1" x 6", 16 feet long?

6. What will the lumber in number 5 cost at $30 per M?