Find the per cent of the total railway mileage in each of the six continents. 2. The foreign-born population of the United States by countries for the years 1890 and 1900 was as follows: Find the rate per cent of increase or decrease. 233,500 3. A dealer buys goods at a discount of 40% off the list price, and sells them at 2% below the list price. What per cent of profit does he make? 4. Eggs are bought at the rate of 5 for 4, and sold at the rate of 4 for 5. What per cent of profit is made? 5. A house lot is sold for $1560 at a profit of $120. Find the rate per cent of profit. 6. Meat is sold at 18 per pound at a profit of 20%. Find the cost price per pound. 7. If the butcher has to pay 1 per pound more for the meat, how must he sell it to make a profit of 25% ? 8. A piano is sold for $470 at a loss of 6%. What would the gain per cent have been if the piano had been sold for $520 ? 9. A tradesman buys at a discount of 10%, and sells at an advance of 15% on the nominal cost price. Find his rate per cent of profit. 10. A book costs the publisher 60 for printing and publishing. At what price should he sell the book in order that he may make a profit of 20%, after paying the author 10% on the selling price? 11. What should be the selling price of an article which costs $15, so that a profit of 20 % may be made after giving the dealer a discount of 10% ? 12. A tradesman marks his goods at 25% above cost, but allows the customer 6% discount. What per cent of profit does he make? 13. Tea is sold at 60 per pound at a profit of 331%. If the total gain is $15, how much tea is sold? 14. A man buys a house for $4000 which he rents for $40 per month; his taxes are 3% on a valuation of $3000. What per cent does his money yield? 15. A merchant marks his goods 20% above cost. What discount does he give if he sells at cost? What is interest? principal ? Amount? INTEREST How is it reckoned? What is the How many days are commonly taken for a month? For a year? Example 1. Find the interest on $670 at 5% from Jan. 14 to Aug. 10. Find the interest and amount of: 2. $670 for 1 yr. 6 mo. at 7%. 3. $1260 for 1 yr. 3 mo. at 8%. 4. $385 for 1 yr. 4 mo. 12 da. at 7 %. 7. $783 for 1 yr. 1 mo. 10 da. at 4%. 13. $960 for 8 mo. 17 da. at 7%. 14. $2911.25 for 1 yr. 7 mo. 16 da. at 4%. 18. $1975.14 from Feb. 8 to Nov. 4 at 31 %. 19. $1218 from March 6 to Nov. 1 at 51 %. 20. $1788 from Feb. 14 to Dec. 20 at 71 %. EXACT INTEREST Interest reckoned on the basis of 365 days to the year is called exact interest. Exact interest is used by the United States Government and sometimes in business transactions. Example. Find the exact interest on $2384.50 from Jan. 12 to July 5 at 5%. SOLUTION. From Jan. 12 to July 5 there are (19+ 28 +31 + 30 + 31 +30 +5) days = 174 days. $2384.50 x .05 × 17 exact interest. 36 $2384.50 x .05 x 174 = 365 EXERCISE 120 Find the exact interest on : 1. $913 from Jan. 4 to Feb. 4 at 5%. 2. $731.11 from Jan. 14 to Jan. 28 at 7 %. 10. $3561.50 for 81 da. at 5%. INVERSE QUESTIONS IN INTEREST Example. What principal will produce $78.75 interest in 75 days at 71% ? $100 produces $7.50 in 1 yr., or 360 days. In 75 days $100 produces In 75 days $1 produces 75% of $7.50. 360 of 75% of $7.50. It will take as many dollars to produce $78.75 in 75 days as the sum produced by $1 in 75 days is contained. times in $78.75. Therefore, $78.75 is to be divided by (1 of 75× $7.50). 360 1 75 7.50 78.75÷(100×75 × 7.50)=78.75 × 109 × 10.5 x 4 x 120 = 5040. $5040 will produce $78.75 in 75 days at 71 %. EXERCISE 121 What principal will produce R 1. $60 in 11 yr. at 8% ? 2. $120 in 2 yr. at 5% ? 3. $135 in 1 yr. 6 mo. at 9% ? 5. $144 in 1 yr. 4 mo. at 41% ? 6. $12 in 1 yr. at 4% ? 7. $21 in 1 yr. at 31%? 8. $84 in 3 yr. 6 mo. at 3% ? 10. |