Question

When students are admitted to a specific university, they are given a seven (7) digit identification number (NNNNNNN). If the first digit must be either a 0 or 1, how many identification numbers are possible?

Answer 1

Explanation:

so, we have 1 position with 2 options (0 or 1).

and 6 positions with 10 options (0 to 9).

so, we have

2×10×10×10×10×10×10 = 2×10⁶ = 2,000,000

different identification numbers possible.