Question

A key code must contain 4 numerals. There are 10 numerals available. Using

these numerals, how many different key codes may be created?
O A. 180
B. 210
O C. 3,060
O D. 5,040​

Answer 1

B, 210

Explanation:

there is 10 options for the first one, 9 option for the second, 8 options for the third and 7 for the last. 10*9*8*7=5040, which is d

Answer 2

First number can be 1 out of 10

Second number can be 1 out of 9

Third number can be 1 out of 8

Fourth number can be 1 out of 7

Total combinations = 10 x 9 x 8 x 7 = 5,040

The answer is D. 5,040