The number of different seven-digit numbers that can be written using only the three digits 1, 2, and 3 with the condition that the digit 2 occurs twice in each number is a. ${}^2{P}_{52}^5$ b. ${}^7{C}_{22}^5$ c. ${}^7{C}_{25}^2$ d. none of these

Views: 706 students