 | David Steel - 1805 - 392 σελίδες
...&c. are in arithmetical progression, decreasing by 4. PROPOSITION I. To find the sum of the series, multiply the sum of the extremes by half the number of terms. The product will be the answer. EXAMPLE 1. The sum of a number of terms, increasing by 3, the extremes... | |
 | Charles Butler - 1814 - 540 σελίδες
...to find the sum of all the terms. RULE. Add the least and greatest terms together, multiply the sum by half the number of terms, and the product will be the sum required. EXAMPLES. 1. The least term is 3, the greatest 17, and the number of terms 8, in an arithmetical... | |
 | Thomas Keith - 1822 - 354 σελίδες
...progression, to find the sum o£ the terms. Rule. To the least term add the greatest, multiply the sum by half the number of terms, and the product will be the sum of the terms. Prop. 2. Given the least term, the greatest term, and the number of terms, to find the common... | |
 | Charles Tayler - 1824 - 350 σελίδες
...whatever, and furnishes the following general rule, viz. Multiply the sum of the jirst and last term by half the number of terms, and the product will be the sttm of the -whole progression. 320. From the formula S = ('2 a + n—\. b}-, any three of m the four... | |
 | Zadock Thompson - 1832 - 186 σελίδες
...number of terms given to find the sum of the series. RULE. — Multiply half the sum of the extremes by the number of terms, and the product will be the sum of the series. 2. How many times does a common clock strike in 12 >ours? 1+12-J-2X 12=78 Ans. 3. Thirteen persons... | |
 | Zadock Thompson - 1832 - 182 σελίδες
...number of terms given to find the sum of the series. RULE. — Multiply half the sum of the extremes by the number of terms, and the product will be the sum of the series. 3. How many tunes does a common clock strike in 12 hours? l_j_12-i-2X 12=78 Ans. 3. Thirteen persons... | |
 | George Alfred - 1834 - 336 σελίδες
...of terms, and half the product will be the sum of all the terms ; or, multiply the sum of 'the two extremes by half the number of terms, and the product will be the sum of all the terms. EXAMPLES. 1. A merchant sold 19 yards of shalloon at 3cts. for the'first yd. 5cts. for... | |
 | Francis Walkingame - 1835 - 270 σελίδες
...terms. RULE I. The first, second, and third terms given, to find the fifth. Multiply the sum of the two extremes, by half the number of terms, and the product will be the total of all the terms. • EXAMPLES. (1) How many strokes does the hammer of a clock strike in 12... | |
 | George Willson - 1836 - 202 σελίδες
...first term of a series, the last term, and the number of terms being given, to find the sum. RULE. — Multiply the sum of the extremes by half the number of terms ; or, multiply by the whole number of terms, and take half the product. 1 . How many strokes does the... | |
 | George Willson - 1838 - 194 σελίδες
...first term of a series, the last term, and the number of terms being given, to find the sum. RULE. — Multiply the sum of the extremes by half the number of terms ; or, multiply by the whole number of terms, and take half the product. » 1. How many strokes does... | |
| |
Multiply the sum of the extremes by half the number of terms, and the product will be the required sum. 
