13. What will be the cost of 66 doz. pens at 42 cents per gross of 12 doz.? 14. A certain quantity of hay feeds 15 horses 56 days. How long will it feed 14 horses? 15. A merchant bought 9 pieces of cloth, each containing 24 yards, for $189. What was the price per yard? MULTIPLICATION OF FRACTIONS. 619. Oral Exercises. What is of 2 fifths? Of 4 sevenths? Of 6 elevenths? x; that is, the product of the numerators is divided by the = Show by a diagram that 2 x 3 tenths 3 fifths. = DIVISION OF FRACTIONS. 625. Oral Exercises. 3 fourths is contained in 4 fourths how many times? 4 fourths 3 fourths =? 1+= how many thirds? 626. Give answers in improper fractions. 1÷ 3 =? 1÷=? Can you show by a diagram that 1 ÷ } = 1} = { ? 627. Divide by . 1÷=? We can divide by reducing both fractions to a common denominator: 628. To divide by , we multiply by what fraction? 629. Divide by 1%. is contained in 1, 16 times. In, it is contained of 15 times. 630. To divide by, we multiply by what? 631. Can you give a rule for dividing by a fraction? 632. N. B. Change mixed numbers to improper fractions. 635. Oral Problems. Give analysis of each: 1. If base-balls are worth of a dollar each, what will be the cost of 16 base-balls? 2. Paid $12 for base-balls, at of a dollar each. How many were bought? 3. What is the cost of 2 feet of ribbon at 30 cents per yard? 4. Find how much a yard of ribbon is worth, if yard costs 20 cents. 5. If it takes yard of material to make one waist, how many can be made from a piece containing 24 yd.? 6. If 18 jackets require 24 yards of cloth, how much is needed for 1 jacket? 7. A man had 60 acres of land. How many acres had he left after selling of his land? 8. After spending of his money, a person had $36 remaining. How much money had he at first? 9. If tea is worth of a dollar per pound, how much can be bought for of a dollar? 10. When tea is $.50 per pound, how much can be bought for $.75? 11. When silk is selling at $.75 per yard, how much can be bought for one-fourth of a dollar? 12. Find the cost of a gallon of milk at the rate of 9 cents for 3 pints. 13. of a gal. of milk costs 94. What is the price per gal. ? 14. of what number is 12? 15. 1 yard and 1 foot of wire cost 16 cents. How much must be paid for a yard? |