 | Sandhurst roy. military coll - 1859 - 672 pages
...and 20 be added to them respectively, they are in geometrical progression. Determine the numbers. 3. Find the number of combinations of n things taken r at a time. From a company of soldiers, mustering 96, a picket of 12 men is to be selected : determine in... | |
 | Isaac Todhunter - 1860 - 620 pages
...article 491, the r things which form the given combination can be arranged in \r_ different ways. 494. To find the number of combinations of n things taken r at a time. The number of combinations of n things taken r at a time is n(nl)(n-2) ...... (nr + l) ~ ~E For... | |
 | Horatio Nelson Robinson - Algebra - 1863 - 432 pages
...set, is equal to the continued product of the natural numbers from n down to 1, inclusive. 339. To find the number of combinations of n things taken r at a time. Now it is evident that all of the P permutations can be obtained, by subjecting the r things... | |
 | Horatio Nelson Robinson - Algebra - 1864 - 444 pages
...set, is equal to the continued product of the natural numbers from n down to 1, inclusive. 339. To find the number of combinations of n things taken r at a time. Let Z = the number of combinations of n things, taken r in a set ; P= the number of permutations... | |
 | Thomas Kimber - Mathematics - 1865 - 302 pages
...that the sum may be 45 ? Find the sum of 8 terms of the geometrical progression 4, 2, 1, i .... 6. Find the number of combinations of n things taken r at a time. Out of 12 consonants and 4 vowels how many words can be formed, each containing 3 consonants... | |
 | Isaac Todhunter - Algebra - 1866 - 580 pages
...491, the r things which form the given' combination can be arranged in \r_ different ways. 494. To find the number of combinations of n things taken r at a time. The number of combinations of n things taken r at a time is n(nl)(n-2) (n-r+l) •' . — •... | |
 | Joseph Ficklin - Algebra - 1874 - 446 pages
...constitute all the different products of the rth degree, of which the letters are capable. 468. To find the number of combinations of n things, taken r at a time. Denote the number of combinations of n things, taken г at a time, by Cr, and the number of permutations... | |
 | Sir George Greenhill - Mathematics - 1876 - 318 pages
...of roots three only are distinct, and the roots Va* are a, a, a 6. Investigate the formula for the number of combinations of n things taken r at a time, without assuming the formula for permutations. A selection of c things is to be made, part from a group of a things and the remainder from a group... | |
 | J. G - 1878 - 408 pages
...BCDE where j^- is constant ; :. A oc BCDE. IV. PERMUTATIONS AND COMBINATIONS. Besides being able to find the number of combinations of n things taken r at a time by assuming the formula for the number of permutations, the student should be able to obtain the... | |
 | University of Madras - 1879 - 674 pages
...6. If the j)<* term of a series in HP is g and the g<* term j» show that the pqt!i term is 1. IV. Find the number of combinations of n things taken r at a time. In how many ways can a pack of 52 cards be distributed equally among four persons so that, —... | |
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Cn,r or nCr, the number of combinations of n things taken r at a time (without repetitions). The form nCr or even "C, is widely used but the notation Cn,r or C(n,r) or ( J is to be preferred. 6. Roman numeral for "hundred. 
