Answer:
<em>19800 seconds, or 330 minutes, or 5 hours + 30 minutes</em>
Step-by-step explanation:
<u>Number Permutations</u>
We know the phone number has 7 digits, 4 of which are known by Mark. This leaves him 3 digits to guess with. We also know the last one is not zero. The number can be represented as
XXY
Where X can be any digit from 0 to 9 and Y can be any digit from 1 to 9. The first two can be combined in 10x10 ways, and the last one can be of 9 ways, this gives us 10x10x9 = 900 possible permutations.
If each possible number takes him 22 seconds, every possibility will need
22x900=19800 seconds, or 330 minutes, or 5 hours + 30 minutes
Answer:
its actually D :0
Step-by-step explanation:
Answer:

Step-by-step explanation:
Given: There are 2 classes of 25 students.
13 play basketball
11 play baseball.
4 play neither of sports.
Lets assume basketball as "a" and baseball as "b".
We know, probablity dependent formula; P(a∪b)= P(a)+P(b)-p(a∩b)
As given total number of student is 25
Now, subtituting the values in the formula.
⇒P(a∪b)= 
taking LCD as 25 to solve.
⇒P(a∪b)= 
∴ P(a∪b)= 
Hence, the probability that a student chosen randomly from the class plays both basketball and baseball is
.