Probability that number will include at least 1 seven is .
<u>Step-by-step explanation:</u>
Here we have , if i were to randomly generate a 4-digit number, We need to find how likely is it that my number will include at least 1 seven . Let's find out:
Out of 10 digits ( 0,1,2,3,4,5,6,7,8,9) , We are supposed to find probability to generate a 4 digit number with at least one times 7 . We can find this as Probability for at least one 7 = 1 - Probability for no 7
Total number of combinations =
Total number of combinations without 7 =
Probability of Number without 7 =
⇒ Probability of Number without 7 =
⇒ Probability of Number without 7 =
∴ Probability for at least one 7 = 1 - Probability for no 7
⇒
⇒
Therefore ,Probability that number will include at least 1 seven is .