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. Algebraical Exercises and Examination Papers - Page 123by Henry Sinclair Hall, Samuel Ratcliffe Knight - 1887 - 181 pagesFull view - About this book
| 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... | |
| Education Ministry of - 1860 - 1130 pages
...^L~^ j- * — !*"_^? _ 2* + 5 ' 2 ^ 4 ~ 3 " 8 ( ' \x + y = b. (3.) x ! — -0/5* + 3-45 = 0. (16.) 6. Find the number of combinations of (n) things taken (r) at a time. (12.) 7. Prove the binomial theorem for a positive integral index. (12.) Expand (3x — 7) 8... | |
| Isaac Todhunter - 1860 - 620 pages
...491, the r tilings 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) ^7 For the number... | |
| 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. Now it is ^vident that all of the P permutations can be obtained, by subjecting the r things... | |
| 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 - 618 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) (n-r+ 1) ~Tr " ' For the... | |
| 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... | |
| Oxford univ, local exams - 1875 - 478 pages
...prove that the third term of the geometrical series is greater than the third term of the other. 3. Find the number of combinations of n things taken r at a time. If the number of combinations of 16 things taken r at a time is to the number of combinations... | |
| 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... | |
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