Question

Zip codes for the Houston area are five digit numbers with 7 as the first 2 digits of each zip code. The third digit can be 0, 3, 4 or 5. The remaining digits can be any digit. How many possible zip codes are there in the Houston area

Answer 1

Answer:

There are 400 possible zip codes in the Houston area

Step-by-step explanation:

Here, we want to calculate the possible number of zip codes in the Houston area

We have 5 digits to form

77 is the first two digits ( this is fixed)

For the third digit, we are selecting 1 number out of 0,3,4 or 5

This means 4 C 1

The remaining digits can be any digits

We have 0-9, a total of 10 digits

The first will be 10 C 1 and the second last digit too is 10 C 1

So the number of possible zip codes will be;

4 C 1 * 10 C 1 * 10 C 1

= 4 * 10 * 10 = 400 possible zip codes