 | Harvey Goodwin (bp. of Carlisle.) - Mathematics - 1847 - 136 pages
...together, is to the number taken p + 2 together as a : b. Find n. Example: a = 5, 6=18, p = 3. p. The number of permutations of n things taken r together : the number of permutations taken r — 1 together :: 10 : 1, and the corresponding combinations :: 5 : 3. Find the values of n... | |
 | James Wharton - 1860 - 176 pages
...original number that the combinations of the remaining things, taken 2 together, may be 15 ? (18.) The number of permutations of n things taken r together : the number of permutations of n things taken i — 1 together : : 42 ; 1 ; and the corresponding combinations : : 1 : 1; find the values... | |
 | Harvey Goodwin - 1862 - 174 pages
...to the number taken p + 2 together as a : b. Find n. Example: a = 5, J = 18, j> = 3. * 3—2 9. The number of permutations of n things taken r together : the number of permutations taken r — 1 together :: 10 : 1, and the corresponding combinations :: 5 : 3. Find the values of n... | |
 | James Hamblin Smith - Algebra - 1870 - 478 pages
...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... | |
 | 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... | |
 | Howard Candler - 1885 - 116 pages
...quantities, ie, generally, to incommensurable quantities. PERMUTATIONS AND COMBINATIONS. SG. To find the number of Permutations of n things taken r together. The number of Permutations of n things taken one together is n. Remove one of these things, a. The number of Permutations of the remaining... | |
 | Charles Smith - Algebra - 1888 - 680 pages
...a, b, c, d; the permutations two at a time are ab, ba, ac, ca, ad, da, be, cb, bd, db, cd, and dc. The 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... | |
 | Edward Albert Bowser - Algebra - 1888 - 868 pages
...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... | |
 | 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 (1)... | |
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To find the number of permutations of n different things taken r at a time. 
