A code consists of two different letters followed by 4 different digits. How many total different codes can be generated. class 11 permutation and combination
Answers
Step-by-step explanation:
There are as many codes as there are ways of filling 4 vacant places in succession by the first
10 letters of the English alphabet, keeping in mind that the repetition of letters is not allowed.
The first place can be filled in 10 different ways by any of the first 10 letters of the English
alphabet following which, the second place can be filled in by any of the remaining letters in 9
different ways. The third place can be filled in by any of the remaining 8 letters in 8 different
ways and the fourth place can be filled in by any of the remaining 7 letters in 7 different ways.
Therefore, by multiplication principle, the required numbers of ways in which 4 vacant places
can be filled is 10 * 9 * 8 * 7 = 5040
Hence, 5040 four-letter codes can be formed using the first 10 letters of the English alphabet,
if no letter is repeated.
Answer:
i m in 8th standard sorry i don't know