A security alarm requires a four-digit code. The code can use the digits 0-9 and the digits cannot be repeated

Which expression can be used to determine the probability of the alarm code beginning with a number greater than 72

(@P}) (P3)

10P4

(25) (C3)

1004

60P; ) (gP3)

10P4

1064) (C3)

10C

A is the right answer. The probability of the alarm code beginning with a number greater than 7 = ²P₁*⁹Pₐ / ¹⁰⁰P₄

Step-by-step explanation: Given:A security alarm requires a four-digit code. The code can use the digits 0-9 and the digits cannot be repeated. there is only 2 numbers which are greater than 7 i. e. 8 and 9. there is 2 possibility for first place. For the remaining 3 digits there is 9 possibilities (including 1 which would left after choosing 1 from first place) No of ways for the alarm code beginning with a number greater than 7=²P₁*⁹P₃.

Total ways of code with 4 digits=¹⁰P₄

Therefore the probability of the alarm code beginning with a number greater than 7=²P₁ * ⁹P₃ / ¹⁰P₄ (this is a fraction)