 | Horatio Nelson Robinson - 1859 - 348 σελίδες
...which is twice the sum of the series. Dividing 80 by 2 gives 40, which is the sum required. Hence, RULE. Multiply the sum of the extremes by the number of terms, and divide the product by 2. EXAMPLES. 1. The extremes are 5 and 32, and the number of terms 12 ; •what... | |
 | Horatio Nelson Robinson - 1860 - 444 σελίδες
...equals 80, -which is twice the sum of the series ; and 80 —• 2 = 40, the sum of the series. Hence RULE. Multiply the sum of the extremes by the number of terms, and divide the product by 2. EXAMPLES FOR PRACTICE. 1. Find the sum of the series the first term of which... | |
 | Benjamin Greenleaf - 1861 - 338 σελίδες
...multiplied by the number of terms, the product will be double the sum of either series. Hence, RULE 1. — Multiply the sum of the extremes by the number of terms and half the product will be the sum of the series. Or, RULE 2. — Multiply the sum of the extremes by half the number of terms, and... | |
 | Daniel Adams - 1861 - 452 σελίδες
...$124, $118, $112, $106, $100, form a descending arithmetical progression, and to find the sum due, multiply the sum of the extremes by the number of terms, and take half the product, thus : $142 + $100=$242; and $242 x 8=$1936, which -H 2=Ans. EXAMPLES. 2. A... | |
 | Horatio Nelson Robinson - 1866 - 328 σελίδες
...following RULE. Multiply the sum of the extremes by half the number of terms. EXAMPLES FOR PRACTICE. 1. The first term of an arithmetical series is 5, the last term 92. and the number of terms 30 ; what is the sum of the terms ? Ans. 1455. 2. The first term of... | |
 | Henry Bartlett Maglathlin - 1869 - 332 σελίδες
...half of 84, or of 14 X 6, is the sum of one of the series. Hence, to find the sum of all the terms, Multiply the sum of the extremes by the number of terms, and take half the product. Exercises. 1. The clocks of Venice strike from 1 to 24 ; how many strokes do... | |
 | Benjamin Greenleaf - 1870 - 336 σελίδες
...multiplied by the number of terms, the product will be double the sum of either series. Hence, RULE 1. — Multiply the sum of the extremes by the number of terms and Jialf the product will be the sum of the series. Or, RULE 2. — Multiply the sum of the extremes by... | |
 | Benjamin Greenleaf - 1871 - 350 σελίδες
...multiplied by the number of terms, the product will be double the sum of either series. Hence, RULE 1. — Multiply the sum of the extremes by the number of terms and half the product will be the sum of the series. Or, RULE 2. — Multiply the sum of the extremes by half the number of terms, and... | |
 | Robert Stewart (of Dundee.) - 1871 - 248 σελίδες
...means. CASE I. When the extremes and the number of terms are given, to find the sum of the series. RULE. — Multiply the sum of the extremes by the number of terms, and half of the product is the sum of the 1. The extremes of an arithmetical series are 1 and 147, and the number... | |
 | Henry Bartlett Maglathlin - 1873 - 362 σελίδες
...half of 84, or of 14 X <i, is the sum of one of the series. Hence, to find the sum of all the terms, Multiply the sum of the extremes by the number of terms, and take half the product. Exercises. 1. The clocks of Venice strike from 1• to 24 ; how many strokes... | |
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RULE.* — Multiply the sum of the extremes by the number of terms, and half the product will be the answer. 
