<h2>
Answer:</h2>
The probability that a code starts with the number 7 is:
1/10
<h2>
Step-by-step explanation:</h2>
There are total 10 digits:
0 1 2 3 4 5 6 7 8 9
Also, the total number of codes that are possible using these digits are:
1000
( Since there are 10 choices for first place, 10 for second and 10 for third as well
Hence, total possibilities are: 10×10×10=1000 )
Also, if the first place of the code is fixed with number 7.
So, we need to chose the digits for second and third place.
Hence, total codes whose first digit is 7 are:
100
( Since the choice for first place is fixed and for second and third place we have 10 choices i.e. total such cases are: 1×10×10=100 )
Hence, the probability is calculated as:
Probability=100/1000
=1/10
