 | Warren Colburn - 1830 - 288 σελίδες
...the terms are now equal, and one of them being multiplied by the whole number of terms will give the whole sum : thus ' Hence, the sum of a series of numbers...half of the product of the number of terms by the mm of thejirst and last terms. Example. How many strokes does the hammer of a clock strike in 12 hours... | |
 | Nathan Daboll - 1831 - 246 σελίδες
...; required the sum of the series. 23+3=26 sum of the extremes. Then 26 x 11 -1-2=143 the Answer. 2. How many strokes does the hammer of a clock strike in 12 hours. Ans. 78. 3. A merchant sold 100 yards of cloth, viz. the first yard for 1 ct. the second for 2 cts.... | |
 | Thomas Conkling (W.) - 1831 - 302 σελίδες
...come to? Ans. 125i. The first term is 1, and the last, 4/. 1 9s. or 99s. proceed according w rule. 3. How many strokes does the hammer of a clock strike in 12 hours? ADS. 7S As the common difference is 1, the extremes are 1, and 12; for the clock strikes 1, at one... | |
 | Michael Walsh - 1831 - 348 σελίδες
...two extremes by the whole number of terms, the product is the total of all the terms. EXAMPLES. 1. How many strokes does the hammer of a clock strike in 12 hours ? 12 -f- 1 = 13 then 13 X 6 = 78. Ans. • 2. A man buys 17 yards of cloth, and gave for the first... | |
 | Francis Walkingame - 1832 - 224 σελίδες
...product is the total o| all the. terms: or thus, IFLN are given to find S. N F+Lx— =8-' 2 EXAMPLES. 1. How many strokes does the hammer of a clock strike in 12 hours? 12+1=13, then 13X6=78. 2. A man buys 17 yards of cloth, and gave for the first yard 2t. and for the... | |
 | Francis Walkingame - 1833 - 204 σελίδες
...Multiply the sum of the extremes by the number of terms, and half the product will be the answer.* (1) How many strokes does the hammer of a clock strike in 12 hours ft (2) A man bought 17 yards of cloth, and gave for the first yard 2i. and for the last 1 Oí. What... | |
 | Richard Frederick Clarke (the elder.) - 1833 - 158 σελίδες
...progression are 4 and 200, and the number of terms 20. Required the sum of the terms. Answer, 2040. 3. How many strokes does the hammer of a clock strike in 12 hours ? Answer, 78. 4. In Venice the clocks strike continually on to 24 o'clock ; how many are the strokes... | |
 | Charles Davies - 1833 - 284 σελίδες
...term 100 last term 102 sum of extremes 1 1 half the number of terms 1122 sum of series. Ans. 1123. 2. How many strokes does the hammer of a clock strike in 12 hours ? Ans. 7& 13. If 100 eggs were placed in a right line, exactly one yard from each other, and the first,... | |
 | Francis Walkingame - 1835 - 270 σελίδες
...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 hours? Ans. 78. 12 + 1 — 13 the sum of the two extremes. 12-f-2 = 6 half the number of terms. 13 x 6=78... | |
 | George Willson - 1836 - 202 σελίδες
...half the number of terms ; or, multiply by the whole number of terms, and take half the product. 1 . How many strokes does the hammer of a clock strike in 12 hours ? Half number of terms =6. Extremes 1 + 12=13. 13x6=78. Ans. PROBLEM II. — The first term, the number... | |
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Hence, the sum of a series of numbers in progression by difference is one half of the product of the number of terms by the sum of the first and last terms. 
