| James Hamblin Smith - Algebra - 1870 - 478 pages
...letters P, Q and JR taken two at a time are six in number, thus : P,Q; P,R; Q,P; Q,R; R, P ; R, Q. 404. To find the number of permutations of n different things taken r at a time. Let a,b,c,d... stand for n different things. First to find the number of permutations of the n things... | |
| James Hamblin Smith - Algebra - 1872 - 454 pages
...and R taken two at a time are six in number, thus : P,Q; P,R; Q, P ; Q, R; R, P ; R, Q. 404. Tofind the number of permutations of n different things taken r at a time. Let a,b,c,d... stand for и different things. First to find the number of permutations of the n things... | |
| Braithwaite Arnett - Mathematics - 1873 - 120 pages
...being performable in an ways, the whole number of ways of performing all the compound processes is II. The number of permutations of n different things taken r at a time III. The number of permutations of n different things taken r at a time, when each may be repeated... | |
| R. M. Milburn - Mathematics - 1880 - 116 pages
...• arrangements that can be made of them, without reference to the order in which they appear. 77. The number of permutations of n different things taken r at a time =n(n—\)(n—2) .... (n— r+i). 78. The number of permutations of n different things taken all together... | |
| James Hamblin Smith - Algebra - 1882 - 414 pages
...letters P, Q, and R taken two at a time are six in number, thus : P,Q; P,R; Q,P; Q, R ; R, P ; R, Q. 404. To find the number of permutations of n different things taken r ai a time. Let a,b, c, d ... stand for n different things. First to find the number of permutations... | |
| Edward Albert Bowser - Algebra - 1888 - 868 pages
...letters a, b, c, taken three at a time, form but one combination. 180. The Number of Permutations. — To find the number of permutations of n different things, taken r at a time. Let the different things be represented by n letters, a, 6, c, Set a aside ; write down the other n... | |
| Charles Smith - Algebra - 1888 - 680 pages
...number of permutations of n different things taken r at a time is denoted by the symbol %РГ 237. To find the number of permutations of n different things taken r at a time. Let the different things be represented by the letters a, b,c, It is obvious that there are n permutations... | |
| Webster Wells - Algebra - 1890 - 604 pages
...permutations of the letters taken two at a time is equal to n(n-1). 542. We will now discuss the general case. To find the number of permutations of n different things taken r at a time. Consider the letters .., a.. Take any permutation containing r letters, for example the one consisting of the first... | |
| Webster Wells - Algebra - 1890 - 560 pages
...a time is n(n — l)(n — 2)"-[n — (r — 1)] ; that is, .J>- = n(nl)(n-2)...(nr + l). (1) Note. The number of permutations of n different things taken r at a time, is usually denoted by the symbol nP-. 543. If all the letters are taken together, r = n, and formula... | |
| Walter William Rouse Ball - Mathematics - 1890 - 512 pages
...be taken one at a time in n separate ways. 369. Number of permutations of n things taken r together. The number of permutations of n different things taken r at a time is given by the formula BPr = n(«-l) (nr + 1). Let us denote the things by the letters a,b,c, ....... | |
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