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
The answer is no. Because solution (a,b) means x=a, y=b.and we have a-b=5. And (b,a) would mean x=b and y=a but then x-y=b-a=-(a-b)=-5≠5. So the pair (b,a) is not a solution.
Answer:
hope this helps you look it once.
2x=y
two times the number of minutes = the amount of pages
