Question

the value of 25c22-24c21 is​

Answer 1

Answer:

Given, P(n,r) = 2520 n!(n - r)! = 2520 ...(1) C(n,r) = 21 n!r!(n - r)! = 21 ....(2)comparing (1) and (2), we get, 2520r! = 21 r! = 120 r = 5 Now, P(n,5) ...