The number of seven-digit integers, with sum of the digits equal to 10 and formed by using the digits , and only, is:
Explanation for correct option:
Forming digit number:
The digits with possible combinations to form - digit number whose sum is are
Case :
Case : .
So total Number of possible seven-digit numbers is
Therefore, the number of seven-digit integer formed is .
Hence, the correct answer is option (C).