• # question_answer The number of zeroes at the end of ${{15}^{30}}\times {{10}^{12}}$ is A)  30                    B)  12        C)         42        D)         6

${{15}^{30}}\times {{10}^{12}},$ number of zeroes in any product depends upon the presence of number of 5's and number of 2's in it  ${{15}^{30}}\times {{10}^{12}}={{3}^{30}}\times {{5}^{30}}\times {{2}^{12}}\times {{5}^{12}}={{2}^{12}}\times {{3}^{30}}\times {{5}^{42}}$ The product has 12, 2's and 42 5's. So, the number of zeroes is 12. (5's alone cannot give 10, same number of 2's are required)